Thermo Scientific Prima PRO / Sentinel PRO Mass Spectrometer User's Guide

Prima PRO / Sentinel PRO Mass Spectrometers User Guide P/N 209-230-510 Revision 10 Part of Thermo Fisher Scientific ©2013 Thermo Fisher Scientific Inc. All rights reserved. Thermo Fisher Scientific Inc. (Thermo Fisher) makes every effort to ensure the accuracy and completeness of this manual. However, we cannot be responsible for errors, omissions, or any loss of data as the result of errors or omissions. Thermo Fisher reserves the right to make changes to the manual or improvements to the product at any time without notice. The material in this manual is proprietary and cannot be reproduced in any form without expressed written consent from Thermo Fisher. Revision History Thermo Fisher Scientific Revision Level Date Comments Rev 10 17/02/2016 Ex label changes Prima PRO & Sentinel PRO Mass Spectrometers User Guide v Contents Chapter 1 Introduction......................................................................... 1-1 Chapter 2 Safety Information .............................................................. 2-1 Overview ....................................................................................... 2-1 Safety Conventions and Symbols ................................................. 2-2 System Safety ............................................................................... 2-3 Connecting the Instrument to the Electrical Supply .................. 2-4 Repair & Maintenance ............................................................... 2-4 Changing the Rotary Pump Oil .................................................. 2-4 Switching on the Rotary Pump .................................................. 2-4 High Temperatures .................................................................... 2-5 Rotary Pump Exhaust Outlet ..................................................... 2-5 Inlet System Exhaust ................................................................. 2-5 Gas Mixtures in the Inlet System ............................................... 2-6 Protective Clothing .................................................................... 2-6 Hazardous Materials .................................................................. 2-6 Hazardous Area Systems ........................................................... 2-7 Fan Noise ................................................................................... 2-7 Chapter 3 Site Requirements .............................................................. 3-1 Physical Installation ...................................................................... 3-1 Cable Entries ................................................................................. 3-2 Safe Area Systems ..................................................................... 3-2 Hazardous Area Systems ........................................................... 3-2 Computer and Communications ................................................... 3-2 Fibre Optic Communication ...................................................... 3-3 Hazardous Area Systems ........................................................ 3-3 Environment.................................................................................. 3-4 General ....................................................................................... 3-4 Temperature ............................................................................... 3-4 Humidity .................................................................................... 3-4 Vibration .................................................................................... 3-4 Particulate Contamination.......................................................... 3-4 Altitude ...................................................................................... 3-5 Inlet Gas Connections ................................................................... 3-5 Calibration Gases ....................................................................... 3-5 Sample Gases ............................................................................. 3-6 Exhaust Gas Connections ............................................................. 3-7 Power ............................................................................................ 3-8 Voltage and Frequency .............................................................. 3-8 Requirements ............................................................................. 3-8 Over-current Protection ........................................................... 3-10 Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide vii Contents Power Quality .......................................................................... 3-10 Power Connection .................................................................... 3-10 Other Services ............................................................................. 3-10 Safe Area Systems ................................................................... 3-10 Dry Gas Vent ........................................................................ 3-10 Enclosure Purge .................................................................... 3-10 Hazardous Area Systems ......................................................... 3-11 Dry Gas Vent ........................................................................ 3-11 Rotary Pump Purge ............................................................... 3-11 Compressed Air Requirements ............................................. 3-12 Options ........................................................................................ 3-13 Pump Purge Gas ....................................................................... 3-13 Rotary Oil Box Purge............................................................ 3-13 Rotary Pump Ballast ............................................................. 3-13 Turbo Pump Bearing Purge .................................................. 3-13 External I/O Unit...................................................................... 3-14 viii Chapter 4 Handling & Storage ............................................................ 4-1 Receiving the Instrument .............................................................. 4-1 Unpacking the Instrument ............................................................. 4-2 Storing the Instrument................................................................... 4-2 Chapter 5 Installation & Interconnection ........................................... 5-1 Introduction ................................................................................... 5-1 Positioning the Instrument ............................................................ 5-1 Cable Connections ........................................................................ 5-1 General Requirements ................................................................ 5-1 Safe Area Systems .................................................................. 5-1 Hazardous Area Systems ........................................................ 5-2 Power Connection ...................................................................... 5-2 Safe Area Systems .................................................................. 5-2 Hazardous Area Systems ........................................................ 5-3 Sentinel PRO Sample Pump Power Connection ..................... 5-4 Signal Connection ...................................................................... 5-4 Safe Area Systems .................................................................. 5-4 Hazardous Area Systems ........................................................ 5-4 Gas Connections ........................................................................... 5-4 Other Services ............................................................................... 5-4 Computer System .......................................................................... 5-5 Chapter 6 Commissioning .................................................................. 6-1 General .......................................................................................... 6-1 Procedure ...................................................................................... 6-1 Chapter 7 Startup & Shutdown ........................................................... 7-1 Startup ........................................................................................... 7-1 Procedure ...................................................................................... 7-1 Vacuum Gauge Trip Level......................................................... 7-4 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Contents Starting Scheduled Analysis ...................................................... 7-4 Checking Instrument Tuning and Mass Alignment ................... 7-5 Emission.................................................................................. 7-6 Peak Shape .............................................................................. 7-6 Sensitivity ............................................................................... 7-7 Detectors ................................................................................. 7-8 Mass Alignment ...................................................................... 7-8 Heaters .................................................................................. 7-10 Checking Instrument Status Parameters .................................. 7-10 Shutdown .................................................................................... 7-11 Introduction .............................................................................. 7-11 Shutdown Procedure ................................................................ 7-11 Emergency Shutdown .............................................................. 7-12 Chapter 8 Thermo Fisher Scientific Status & Tuning Parameters .............................................. 8-1 Instrument Status .......................................................................... 8-1 Source Tab .................................................................................... 8-2 Electron Energy ......................................................................... 8-2 Emission..................................................................................... 8-2 Filament Current ........................................................................ 8-2 Filament Current Limit .............................................................. 8-2 Filament Integrity ...................................................................... 8-3 Half Plate 1 and 2 Output Voltages ........................................... 8-3 In Current Limit ......................................................................... 8-3 Ion Energy.................................................................................. 8-3 Repeller Voltage ........................................................................ 8-4 Source Current ........................................................................... 8-4 Source Temperature ................................................................... 8-4 Trap Current ............................................................................... 8-4 Analyser Tab ................................................................................. 8-5 ASU Controller Status ............................................................... 8-5 Cabinet Temperature.................................................................. 8-5 Electronics Temperature ............................................................ 8-5 Magnet Controller Status ........................................................... 8-5 Mass Filter ................................................................................. 8-6 Pressure Set Point ...................................................................... 8-6 System Pressure ......................................................................... 8-6 System Pressure Trip ................................................................. 8-7 Turbo Motor Current ................................................................. 8-7 Turbo Operating Hours .............................................................. 8-7 Turbo Speed ............................................................................... 8-7 Turbo Speed Interlock ............................................................... 8-8 Vacuum ...................................................................................... 8-8 Vent Valve ................................................................................. 8-8 Inlet ............................................................................................... 8-8 Pressure Raw.............................................................................. 8-8 RMS Ambient Temperature....................................................... 8-8 RMS Body Temp ....................................................................... 8-8 RMS Controller Status ............................................................... 8-8 Prima PRO & Sentinel PRO Mass Spectrometers User Guide ix Contents RMS Sample Flow Sensor ......................................................... 8-8 RMS Flow Zero ......................................................................... 8-8 RMS Position ............................................................................. 8-8 Sample Tube Current ................................................................. 8-8 Sample Tube Temperature ......................................................... 8-9 Collector Tab ................................................................................ 8-9 Faraday Deflector....................................................................... 8-9 Multiplier Deflector ................................................................... 8-9 Multiplier Voltage ...................................................................... 8-9 Negative and Positive Quad Lens Voltages ............................... 8-9 Resolution .................................................................................. 8-9 Power .......................................................................................... 8-10 Amplifier +24V........................................................................ 8-10 Analyser Supplies +24V .......................................................... 8-10 Instrument CPU 24V................................................................ 8-10 Fan 24V .................................................................................... 8-10 Inlet Probe Current ................................................................... 8-10 Magnet Supply Current ............................................................ 8-11 Magnet Sync AC ...................................................................... 8-11 Power Controller Status ........................................................... 8-11 Turbo 24V ................................................................................ 8-11 User IO 24V ............................................................................. 8-11 Vent Valve 24V ....................................................................... 8-11 Communications ......................................................................... 8-11 Host Comms Quiet................................................................... 8-11 User I/O 0 Comms Quiet ......................................................... 8-11 User I/O 1 Comms Quiet ......................................................... 8-11 User I/O 2 Comms Quiet ......................................................... 8-11 User I/O 3 Comms Quiet ......................................................... 8-12 VGiNet ..................................................................................... 8-12 Checking Mass Alignment .......................................................... 8-12 x Chapter 9 Fault Diagnosis................................................................... 9-1 Introduction ................................................................................... 9-1 Alarm Conditions .......................................................................... 9-1 Leak Detection .............................................................................. 9-4 Mass Spectrometer Faults ............................................................. 9-5 No Peaks .................................................................................... 9-5 Poor Sensitivity .......................................................................... 9-6 Poor Stability on Startup ............................................................ 9-6 Poor Results Following Calibration ........................................... 9-7 Ion Source and Magnet Pole Pieces Assembly .......................... 9-8 Filament Failure ............................................................................ 9-8 Chapter 10 Maintenance...................................................................... 10-1 Maintenance Schedule ................................................................ 10-1 Procedures ................................................................................... 10-1 Rotary Pump Oil Level ............................................................ 10-1 Cleaning the Cooling Fans ....................................................... 10-2 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Contents Lubricating the Turbo Molecular Pump .................................. 10-3 Dismantling and Cleaning Procedures ........................................ 10-3 Filament ................................................................................... 10-3 Ion Source ................................................................................ 10-5 Magnet Pole Piece Assembly .................................................. 10-8 Fuses ...................................................................................... 10-10 Appendix A Thermo Fisher Scientific Hazardous Area Operation ............................................... A-1 Introduction .................................................................................. A-1 Installation ................................................................................ A-2 General Hazardous Area Work ................................................. A-3 Commissioning and Maintenance ............................................. A-3 Routine Checks ......................................................................... A-4 Hazardous Area – General ........................................................... A-4 Area Classification .................................................................... A-4 Gas Classification ..................................................................... A-5 Methods of Protection ............................................................... A-5 Purge/Pressurisation............................................................... A-5 Flameproof (Europe) or Explosion Proof (North America) .. A-6 Increased Safety ..................................................................... A-7 Non-Electrical ........................................................................ A-7 Purge Operation ........................................................................... A-8 Purge Overview ........................................................................ A-8 Purge Operation Requirements ................................................. A-9 Parameter Measurement ...................................................... A-10 Sample Containment System .................................................. A-11 Definition and Description................................................... A-11 Parameters ............................................................................ A-11 Leakage Handling ................................................................ A-11 Inspection and Testing ......................................................... A-13 Enclosure Leak Testing .......................................................... A-14 Purge Operation and Testing .................................................. A-15 All System Types ................................................................. A-15 ATEX, IECEx and X-Purge Systems .................................. A-15 Z-Purge Systems .................................................................. A-16 Other Hazardous Area Considerations ...................................... A-16 Temperature ............................................................................ A-16 Over-Temperature Protection .............................................. A-16 Batteries .................................................................................. A-17 Dry Gas Vent .......................................................................... A-17 Rotary Vacuum Pump ............................................................. A-18 General ................................................................................. A-18 Thermal Trip ........................................................................ A-18 Purge .................................................................................... A-18 Calibration Panels ................................................................... A-19 Air Conditioner ....................................................................... A-20 Remote / Dual RMS................................................................ A-20 RMS and Instrument in Hazardous Area ............................. A-20 RMS in Hazardous Area and Instrument in Safe Area ........ A-20 Prima PRO & Sentinel PRO Mass Spectrometers User Guide xi Contents Sample Pump (Sentinel PRO Applications) ........................... A-21 Fibre Optic Communications .................................................. A-21 Service Replacement Items ........................................................ A-21 Troubleshooting ......................................................................... A-23 Standards Conformance ............................................................. A-25 xii Appendix B Technical Description: Hardware ......................................B-1 Introduction to the Prima PRO Hardware .................................... B-1 Main Components ..................................................................... B-1 Principle of Operation .................................................................. B-2 Vacuum System ........................................................................... B-4 Ion Source .................................................................................... B-5 Filaments ................................................................................... B-7 Mass Analyser .............................................................................. B-9 Collector ....................................................................................... B-9 Ion Detection .............................................................................. B-10 MCP Detector Assembly ........................................................ B-10 MCP Operation ....................................................................... B-11 Faraday Detector ..................................................................... B-13 Introduction of a Gas Sample .................................................... B-13 Mass Spectrometer Parameters .................................................. B-15 Sensitivity ............................................................................... B-15 Resolution ............................................................................... B-15 Cracking Patterns ....................................................................... B-17 Ion Types ................................................................................ B-17 Molecular Ion ....................................................................... B-17 Isotope Ions .......................................................................... B-17 Fragment Ions ...................................................................... B-18 Multiple-Charged Ions ......................................................... B-18 Rearrangement and Recombination Peaks........................... B-18 Definitions............................................................................... B-19 Appendix C Technical Description: Inlet...............................................C-1 Rapid Multi-Stream Sampler (RMS) ........................................... C-1 Introduction ............................................................................... C-1 Safety ........................................................................................ C-1 Inlet Specification ..................................................................... C-2 Inlet Operation .......................................................................... C-3 General Description ............................................................... C-3 Connection to the Mass Spectrometer ................................... C-4 Seals ....................................................................................... C-4 Inlet Selection ........................................................................ C-5 Calibration Gas Control ......................................................... C-5 Gas Connection ...................................................................... C-6 Exhaust Connection ............................................................... C-7 Heating ................................................................................... C-8 Hazardous Area Systems ....................................................... C-9 Inlet Controller ........................................................................ C-10 General ................................................................................. C-10 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Contents Calibration Valve Drives ..................................................... C-10 Main Body Heater ................................................................ C-10 Sample Tube Heater............................................................. C-11 Flow Sensor ......................................................................... C-11 Digital Inputs ....................................................................... C-11 VGiNet ................................................................................. C-11 Inlet Testing ............................................................................ C-12 Functional Testing ............................................................... C-12 Cross Port Leakage ................................................................. C-14 External Leakage .................................................................... C-15 Maintenance ............................................................................ C-15 Routine Maintenance ........................................................... C-16 Sample Tube Removal ............................................................ C-19 Inlet Ports ................................................................................ C-21 Cleaning Procedure ................................................................. C-21 Inlet Options ........................................................................... C-22 Remote Mounting ................................................................ C-22 Dual RMS ............................................................................... C-23 Solenoid Inlet ............................................................................. C-27 Introduction ............................................................................. C-27 Safety ...................................................................................... C-27 Inlet Operation ........................................................................ C-28 Valve Operation ................................................................... C-30 Capillary Connection ........................................................... C-30 Heating ................................................................................. C-31 Inlet Controller ........................................................................ C-31 General ................................................................................. C-31 Valve Drives ........................................................................ C-32 Manifold Heater ................................................................... C-32 Microcapillary Block Heater ............................................... C-32 Flow Sensor ......................................................................... C-32 Digital Inputs ....................................................................... C-32 VGiNet ................................................................................. C-33 Testing .................................................................................... C-33 Capillary Testing.................................................................. C-33 Valve Function ..................................................................... C-34 Cross Seat Leakage .............................................................. C-34 External Leakage ................................................................. C-35 Maintenance ............................................................................ C-36 Calibration Inlet ................................................................... C-36 Sample Inlet ......................................................................... C-38 Cleaning Procedure .............................................................. C-39 Appendix D Thermo Fisher Scientific Local I/O ............................................................................. D-1 Introduction .................................................................................. D-1 Serial I/O ...................................................................................... D-1 Serial Link Type Selection ....................................................... D-1 Indicators .................................................................................. D-2 Fibre Optic Serial Connection .................................................. D-2 Prima PRO & Sentinel PRO Mass Spectrometers User Guide xiii Contents Discrete I/O .................................................................................. D-4 Supplying Power to the External I/O Circuit ............................ D-4 Indicators................................................................................... D-4 Analogue I/O ............................................................................. D-5 xiv Appendix E Air Conditioner ................................................................... E-1 Introduction .................................................................................. E-1 Normal Operation ........................................................................ E-1 Fault Conditions ........................................................................... E-2 Fault Diagnosis ............................................................................ E-3 Appendix F Regulatory........................................................................... F-1 FCC .............................................................................................. F-1 WEEE .......................................................................................... F-2 China RoHS ................................................................................. F-3 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Chapter 1 Introduction This manual is provided for users, operators, and owners of Thermo Scientific Mass Spectrometers. This manual covers both the Thermo Scientific Prima PRO, Sentinel PRO, Prima PRO Ex (hazardous area), and Sentinel PRO Ex (hazardous area) instrumentation. Note: The name Prima PRO will be used exclusively in subsequent chapters. Sentinel PRO is identical to Prima PRO except for the following:  Inlet: A membrane assembly replaces the Prima PRO capillary, molecular leak, and bypass.  Collector slits: Are 0.36 mm / 0.69 mm as opposed to the standard 1.0 mm / 4.0 mm on the Prima PRO. Information in this is organized in chapters and covers site preparation, installation, commissioning, operation, and maintenance. Technical descriptions of the instrument and various inlet configurations are provided as individual appendices. Contacts For sales and support of the Prima PRO / Sentinel PRO instrumentation, the Thermo Fisher Process Instruments main offices are detailed below. Americas Thermo Fisher Scientific Process Instruments Division 1410 Gillingham Lane Sugar Land, Texas 77478 USA Phone: 713-272-0404 Fax: 713-272-4573 Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 1-1 Introduction Contacts Europe, Middle East, Asia, Africa Thermo Fisher Scientific, Europe Process Instruments Division Ion Path Road Three Winsford Industrial Estate Winsford Cheshire CW7 3GA UK Phone: +44 (0)1606 548700 Fax: +44 (0)1606 548711 China Thermo Fisher Scientific, China Process Instruments Division Building 6, No.27 Xin Jinqiao Rd. Shanghai China 201206 Tel: +86(21)6865 4588 Fax: +86(21)6445 1101 Web Site www.thermofisher.com 1-2 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Chapter 2 Safety Information Overview This chapter contains general safety and operating information applicable to analytical systems that must be understood by all persons installing, using, or maintaining the system. This information is designed to aid personnel in the safe installation, operation, and service of the analyser and sample systems. It is not designed to replace or limit appropriate safety measures applicable to work performed by personnel. Any additional safety and operating measures that are required must be determined by and followed by personnel performing work on the system. It is the responsibility of the user / operator / integrator (hereon referred to as user) to perform risk assessments of the site location, installation and operation of the instrumentation. This manual highlights hazards associated with the instrument and provides details of precautions to be taken to ensure safe operation. The user must account for the information provided and put in place procedures to ensure for the safety of personnel and plant. To ensure personal safety, system integrity, and optimum performance, users should thoroughly understand the content of this manual before installing, using, or performing maintenance on this product. Failure to follow appropriate safety procedures or inappropriate use of the equipment described in this manual can lead to equipment damage or injury to personnel. Any person working with or on the equipment described in this manual is required to evaluate all functions and operations for potential safety hazards before commencing work. Appropriate precautions must be taken as necessary to prevent potential damage to equipment or injury to personnel. Only qualified technical personnel should access the analyser enclosure. If in doubt as to the instructions and information provided or if you have additional questions regarding the product, a service or support request, contact your nearest Thermo Fisher Scientific representative for process mass spectrometers. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 2-1 Safety Information Safety Conventions and Symbols Safety Conventions and Symbols The following conventions and symbols are used throughout this manual to alert users to potential hazards or important information. Failure to heed the warnings and cautions in this manual can lead to injury or equipment damage. Warning / Danger Warning / Danger statements notify users of procedures, practices, conditions, etc. which may result in serious injury or death if not carefully observed or followed. The triangular icon displayed with a warning varies depending on the type of hazard (only two are displayed here). Prohibited These statements explicitly PROHIBIT an action. Ignoring an instruction related to a hazard highlighted with this symbol may cause an unsafe condition that could result in an accident. Caution Cautions notify users of operating procedures, practices, conditions, etc. that may result in equipment damage or cause injury if not carefully observed or followed. Caution Statements accompanied by this caution symbol explicitly require an action be taken. Ignoring an instruction related to a hazard or instruction highlighted with this symbol may cause an unsafe condition which could result in an accident. Note Notes emphasize important or essential information or a statement of company policy regarding an operating procedure, practice, condition, etc.  2-2 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Safety Information System Safety The information in this manual is designed to aid personnel to correctly and safely install, operate, and / or maintain the system described; however, personnel are still responsible for considering all actions and procedures for potential hazards or conditions that may not have been anticipated in the written procedures. If a procedure cannot be performed safely, it must not be performed until appropriate actions can be taken to ensure the safety of the equipment and personnel. The procedures in this manual are not designed to replace or supersede required or common sense safety practices. All safety warnings listed in any documentation applicable to equipment and parts used in or with the system described in this manual must be read and understood prior to working on or with any part of the system. Failure to correctly perform the instructions and procedures in this manual or other documents pertaining to this system can result in equipment malfunction, equipment damage, and / or injury to personnel. Warning! Deviation from the instructions may result in equipment malfunction, equipment damage, and / or injury to personnel. System Safety Read this manual before operating the instrument! In particular, review the following cautionary statements. Caution! Only qualified personnel trained in the safe operation of the Prima PRO / Sentinel PRO hardware should have access to the cabinet door keys. Caution! Never disregard any cautionary or warning instructions. Read and observe all instructions on printed labels fixed to the instrument. Caution! Failure to operate the instrument as specified could impair the protection features provided and described in this guide. Hazards exist within the instrument enclosure, and the remainder of this chapter details any necessary precautions to be taken. Read the following safety notes carefully before attempting to operate or work on the instrument. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 2-3 Safety Information System Safety Connecting the Instrument to the Electrical Supply Caution! Repair & Maintenance  Check that the mains supply satisfies the requirements detailed in Chapter 3: Site Requirements.  Connection must be made by qualified personnel only. Observe the instructions provided in Chapter 3: Site Requirements, and ensure that the connection is consistent with local safety regulations. When performing repair or maintenance on the instrument: Warning! Before attempting to carry out repairs or maintenance, isolate the mains electrical supply. Caution! Maintenance should be carried out by qualified personnel only. Changing the Rotary Pump Oil Warning! Allow the pump oil to cool before draining. Switching on the Rotary Pump Caution! Check that the oil level is between the two markers on the oil level window before switching on the rotary pump. 2-4 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Safety Information System Safety High Temperatures Warning! The following assemblies may attain a surface temperature as listed:  Rapid Multi-Stream Sampler (RMS) and Single Point Inlet System: 120°C.  Single Point Inlet System (High Temperature Version): 230°C.  RMS Sample Probe: 120°C.  Inlet Probe Assembly: 120°C.  Rotary pump operating temperature: 75°C. Rotary Pump Exhaust Outlet Warning! Ensure that the rotary pump is unobstructed. Failure to do so will cause dangerous internal pressures in the pump. This will result in blown seals and bursting of the oil box and could result in physical injury. Inlet System Exhaust Warning! A leak-tight exhaust must be fitted to the inlet system when sampling gas streams which are: Thermo Fisher Scientific  Explosive  Toxic  Asphyxiant Prima PRO & Sentinel PRO Mass Spectrometers User Guide 2-5 Safety Information System Safety Gas Mixtures in the Inlet System Warning! All gases flowing into multi-stream inlets (e.g. RMS) mix in the common exhaust. Consideration should be given to the creation of potentially explosive or toxic mixtures in the valve and exhaust as a result of incompatible sample streams. See “Exhaust Gas Connections” in Chapter 3. Protective Clothing Warning! It is recommended that the following personal protective equipment (PPE) is used when performing the following tasks:  Changing rotary pump oil: Safety glasses, overalls and rubber gloves.  Changing or removing the glass leak: Safety glasses.  Connecting sample lines: Safety glasses.  Changing a filament: Rubber gloves. Hazardous Materials Warning! The substances listed below are potentially hazardous.  Thoria filaments: Thoria is naturally radioactive and should not be ingested. When handling wear rubber gloves. Old filament assemblies can, however, be treated in general waste.  Rotary pump oil: Must not be ingested. It is a possible irritant. Keep away from skin, especially open wounds. Waste oil is to be disposed of in an environmentally responsible manner.  2-6 Gas lines: It is the user’s responsibility to check the integrity of gas lines taking samples to the instrument. Special care must be taken when dealing with toxic gases.  Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Safety Information System Safety Hazardous Area Systems Warning! Specific safety considerations for installation, commissioning, operation, and maintenance of the Prima PRO Ex and Sentinel PRO Ex instruments in hazardous areas are given in Appendix A: Hazardous Area Operation. The points covered in that section must be considered in addition to the points above.  For Ex systems, the instructions in Appendix A: Hazardous Area Operation take precedence over content in the rest of the manual.  For Ex systems, always defer to the instruction in Appendix A: Hazardous Area Operation. Fan Noise Note: At full speed, the noise level from the air conditioner fan can be up to 65 dBA. Although this is below a level considered harmful, it can be intrusive if the installation is in a confined space, laboratory environment, or where ambient background noise levels are low. If the installation is in an environment where ambient temperatures are not expected to exceed 30°C, a speed limiter can be switched in to the fan supply, which will reduce the maximum noise level to < 55 dBA. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 2-7 Chapter 3 Site Requirements Note: Further information on many of the items covered in this chapter can be found elsewhere in this manual or on the installation drawing for the particular instrument configuration.  Physical Installation The instrument comprises a single enclosure fixed to a mounting frame. A vacuum pump (or pumps) is mounted on the frame base below the enclosure. The frame is supplied with wheels brackets for ease of initial positioning. There are three options for the physical installation of the main unit.  Wheels removed, fixed to the floor.  Wheels removed, standing on the floor but fixed to a wall.  Free standing with wheels fitted. Caution! The unit is not suitable for (1) free standing with the wheels removed or (2) fixing to a wall where the base is not in contact with the ground. Note: Thermo Fisher Scientific  The dimensions of the system vary, depending on the options chosen for a particular application, safe / hazardous area, inlet type, mounting method, etc.  The installation drawing for the particular configuration should be consulted for detailed dimensional information. The installation drawing will also provide details of fixing points and additional space required for air flow and service access.  The complete system may include items not mounted on the main instrument frame (IO systems, remote inlet systems etc). Such items are typically wall mounted. The installation drawing should be consulted for details. Prima PRO & Sentinel PRO Mass Spectrometers User Guide 3-1 Site Requirements Cable Entries Cable Entries Safe Area Systems A blank gland plate is supplied in the enclosure base. This is the only place where drilling the enclosure for user cable entries is allowed. See Chapter 5: Installation & Interconnection for further details. Hazardous Area Systems Warning! Heed the following warnings for hazardous area systems: Computer and Communications  No user electrical connections (power or signal) are made within the instrument enclosure.  All electrical connections are to be made to the flameproof box above the main enclosure (or to additional flameproof boxes in the case of extended I/O). See Chapter 5: Installation & Interconnection for further details.  If the fibre optic communication option has been ordered, the fibre connection point is within the enclosure, and this is the only situation where cable entry to the purged enclosure is permitted. See Chapter 5: Installation & Interconnection for further details. See below for details of fibre optic cable requirements. A computer specification can be requested from Thermo Fisher Scientific if required. Most modern PCs are suitable, but they should ideally incorporate at least one serial port. This functionality can be provided through a USB-to-serial converter. Contact the factory regarding compatibility with different versions of Microsoft® Windows® operating system. If a permanent PC connection is planned, the most common configuration, physical space, and a mains power supply are required. The PC can be local to the instrument or remote depending on requirements and the area classification of the instrument location. The PC is connected to the instrument enclosure via a serial link. Connection is to the host terminals on the CPU IO PCB in the bottom left of the enclosure, through the gland plate. Other serial connections, such as link to DCS, are also made here. 3-2 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Site Requirements Computer and Communications Warning! On Ex systems, connection is made to an equivalent set of terminals in the flameproof box above the instrument enclosure. A number of serial formats are possible: a. RS232 simple 3-wire link, transmission distance 5 meters. May be extended by the use of good quality screened cable. b. RS422 4-wire, full duplex link, extended transmission distances. For the host link, this is likely to require an RS422232 converter for connection to the PC (available as an option). c. RS485 2-wire, half duplex link, extended transmission distances. Cannot be used for the host link. Fibre Optic Communication The fibre optic communication option can be used to extend transmission distances for the above communication formats by up to 1000 meters. When selected for any given link (there are five links that can use fibre optic communication), a pair of fibre optic converters is supplied. One is to be fitted in the instrument enclosure and the other at the remote end, PC / DCS. The interconnecting fibre optic cables (a pair of fibre cores for each link) must: a. have ST terminations b. support multimode operation c. be compatible with LED drivers. It is recommended that one or two spare fibre pairs are included in multi-core cable runs to allow for future expansion. It should be noted that selection, installation, and termination of the fibre optic cable is a user / installer responsibility. Hazardous Area Systems Thermo Fisher Scientific Warning! Where fibre optic links are selected for use with a hazardous area system the following additional requirements must be met:  The remote fibre optic converter (i.e. not installed in the purged instrument enclosure) must be located wholly within a safe area or a suitably protected enclosure (e.g. Exd, Exp).  The fibre optic cable must have a suitable degree of protection, e.g. steel wire armour or equivalent. Prima PRO & Sentinel PRO Mass Spectrometers User Guide 3-3 Site Requirements Environment Environment General Note: The system should be located indoors or in an analyser shelter, or similar, to provide for basic physical and weather protection. Contact with water sources, chemicals, etc. should also be avoided. Temperature The operating temperature should be between 12°C and 40°C. Sudden step changes in temperature (>10°C) should be avoided. Humidity Relative humidity should be 90% maximum, non-condensing. Vibration The vibration frequency and amplitude should be within the limits shown in the following table. Table 3–1. Vibration Limits Frequency Maximum Amplitude ≤ 20 Hz 5 mm ≤ 60 Hz 1 mm ≤ 200 Hz 0.05 mm > 200 Hz 0.01 mm Where necessary, the instrument should be isolated from sources of vibration by use of suitable mountings. Transmission of vibration along pipes and conduit should also be considered. Particulate Contamination Note: 3-4  Where possible, the instrument should be positioned in an environment free of particulate contamination.  Although the instrument enclosure is sealed and largely immune to dust, the operation of the air conditioner will become impaired over time and will require more frequent maintenance. Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Site Requirements Inlet Gas Connections  Altitude Inlet Gas Connections Calibration Gases Inspect the condition of the heat exchanger fins on a regular basis. Clean as required. Altitude must be less than 2000 m. Calibration and sample gas lines to single or multi-point inlet options are connected with Swagelok compression fittings (1/8” or 1/4” or 6 mm, as defined in the order). All fittings are supplied with PTFE plugs fitted (ferrules packed separately) to provide a seal during transit. These can be used as seals for unused ports, but it is recommended that for long term use, particularly at elevated temperatures, Swagelok plugs are substituted. Calibration panels (six gas inlets per panel) are used in conjunction with some inlet types to control calibration gas flow. A line pressure of 1 bar(g) (adjustable for fine tuning) will give the required flow rates, typically 150 cm3/min for Prima PRO instruments and 5 l/min for Sentinel PRO instruments. For some inlets (e.g. RMS and solenoid) flow is monitored internally by the system. If the inlet configuration selected does not have this feature external flow monitoring will be required. Calibration gases lines connect to the panel via 1/8” or 1/4” or 6 mm compression fittings, as defined in the order. Calibration gases required for a given application are specified with the quotation or application document. Contact the factory if this document is not available. Note: Depending on complexity and constituents, some calibration gas mixtures may have long purchase lead times. Calibration gases should be of the highest quality with a certificate of analysis from the manufacturer giving a concentration tolerance for each component. Helium gas (for instrument background measurement) should be at least 99.995% pure. Gas consumption will depend on specified use and gas type. Each line selected during calibration will be required to flow for between 15 seconds and 5 minutes, depending on factors such as gas type, line length, line integrity, etc. In addition to calibration cycles, some gases may also be designated for instrument test or check functions. The frequency and duration of these additional duties need to be accounted for in establishing likely consumption rates and to schedule the ordering of replacement cylinders. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 3-5 Site Requirements Inlet Gas Connections Note: The accuracy of analytical data produced by the instrument is directly related to the accuracy, quality, and stability of the calibration gases. In addition to the accuracy of certification, attention should also be given to factors such as shelf life and storage conditions (temperatures and bottle orientation, for example) that could result in effects such as condensation, stratification, or degradation, all of which could influence the quality of calibration. Seek advice from your gas supplier. Double stage regulators with 0-2 bar(g) (adjustable) output stages and 40 bar (maximum) outlet pressure relief should be used with the gas cylinders (pressure relief is not required if the cylinder pressure is less than 40 bar). It is the user's responsibility to provide calibration gas cylinders, regulators, and pipe work from each cylinder to the calibration panel and safe venting of pressure relief valves. Caution! Regulators and line materials must be compatible with the gases in question. The use of good quality regulators ensures reliable calibration gas flow, especially for unattended operations. Sample Gases It is the user’s responsibility to install sample lines to the instrument’s inlet assembly. The line material must be compatible with the sample gas stream composition and operating temperatures. Caution! 3-6  Each sample stream should be reviewed with regard to sample conditioning / filtering.  As a minimum, each line should be filtered to prevent particulate contamination.  Even where dust levels in the sample gas are very low, it is recommended that a 2 µm particulate filter with a capacity appropriate to the dust loading of the sample gas be fitted.  If significant quantities of dust particles < 2 µm are present, a smaller pore size filter should be used.  Precautions must be taken to prevent liquid in any form (liquid condensate, foam, aerosols, etc.) from entering the inlet system. Suitable traps and / or heated lines, avoiding cold spots, should be used. Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Site Requirements Exhaust Gas Connections Sample flow must be regulated. Typical flows are:  0.5 l/min for Prima PRO  5 l/min for Sentinel PRO Flows in the range 0.1to 10.0 l/min for Prima PRO and 2 to 10 l/min for Sentinel PRO can exist in certain configurations / installations. Consult the factory or the manual for the specific inlet type fitted. Exhaust Gas Connections There are two gas outlets from the instrument that should exhaust outside the work area either to atmosphere or a suitable vent system.   Rotary pump exhaust: 1/2” hose connection (2 for some applications). Inlet system exhaust: Connection specific to the inlet type. 1.0" OD tube stub for RMS, 1/4” or 6 mm for most other inlet types. On Sentinel PRO, a sample pump is normally fitted to the exhaust port of the RMS inlet. The inlet exhaust in this case is that of the pump, typically a hose connection, size dependent on the pump size. Note: The following should be taken into account:  Exhaust temperature can reach 120°C depending on inlet type. An exhaust line compatible with the gas composition and temperatures must be used.  To avoid condensate returning to the inlet assembly, it may be necessary to heat the line or fit a suitable liquid trap. Fitting an exhaust line, angled downwards over its full length, will aid in drainage of any condensate and in many instances may be sufficient.  Users are responsible for assessing the composition and physical characteristics of sample streams, the risks of condensation, and taking appropriate measures to protect the inlet system. Caution! Thermo Fisher Scientific  An inert gas feed can be added to the inlet exhaust stream to dilute corrosive, reactive, condensable, or hazardous (e.g. explosive) gas mixtures.  In some instances explosive gas mixtures may form by mixing different process gases in the common exhaust of the inlet system. Prima PRO & Sentinel PRO Mass Spectrometers User Guide 3-7 Site Requirements Power  In other cases, mixed streams can react together to form condensable or polymeric materials.  The addition of an inert gas stream can reduce or avoid the need for the use of special materials, heat tracing of the exhaust line, etc.  Inert gas flow requirements will be application specific.  Assessing the suitability of an inert gas addition to the exhaust stream, its provision, and monitoring are the responsibility of the user. Caution! Interconnection of the two exhaust lines, Rotary and Inlet, MUST be avoided if at all possible. The rotary pump exhaust contains oil mist that could result in serious contamination if allowed to enter the RMS inlet and subsequently the mass spectrometer. If interconnection is unavoidable, it should be positioned as far downstream as possible and a guaranteed positive gas flow provided to the RMS exhaust to reduce the chances of back flow (see above statements on inert gas flow). Refer to the chapter relating to the specific inlet system for further details on the exhaust requirements. It is the user’s responsibility to supply all the necessary pipe work to connect the two exhaust outlets to a suitable location. Power This section provides details on the power requirements for the instrument. Voltage and Frequency A single phase power supply is required – either 115 Vac ( 5 Vac) or 230 Vac ( 10 Vac). Note that voltage and frequency are specified at time of order. Safe area systems will accept either 50 Hz or 60 Hz supplies. Caution!  Ex rated systems for hazardous area operation will only operate at a specific frequency.  Check that the ratings and supply are correct before installation. Requirements 3-8 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Site Requirements Power The instrument must be connected to a clean earth (ground) point (see below). For systems with a single rotary pump and an RMS inlet system, the normal running average power consumptions for safe area and Ex systems are 2.0 kVA and 2.5kVA respectively. Typical startup current profiles (from cold) for these two configurations are shown in Figure 3–1 and Figure 3–2. Safe Area System Startup (240VAC) 35.0 30.0 Startup at 0.1s Rotary pump start RMS current (A) 25.0 20.0 15.0 10.0 RMS heater on RMS heater cycle 5.0 0.0 0.0 4.0 8.0 12.0 16.0 Time (s) Figure 3–1. Typical startup current profile for safe area system (240 Vac) Ex System Startup (240VAC) 35.0 Rotary pump start 30.0 25.0 RMS current (A) Startup at 0.1s 20.0 15.0 10.0 RMS heater on RMS heater cycle 5.0 0.0 0.0 4.0 8.0 12.0 16.0 Time (s) Figure 3–2. Typical startup current profile for Ex system (240 Vac) 120 Vac systems will show approximately twice the above currents. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 3-9 Site Requirements Other Services Over-current Protection Power Quality Power Connection Other Services The incoming power supply must include an over-current protection device rated at a maximum of 40 A continuous operation, but should be capable of withstanding the appropriate startup period as shown above without operating. This normally requires the use of a slowblow fuse or a circuit breaker specified for motor starting. The system power should be free from supply ‘drop-out’ over 1/2 cycle or more. If the local power supply is unreliable or noisy, then power conditioning (e.g. uninterruptible power supply, constant voltage transformer) of appropriate capacity should be installed. Refer to Chapter 5: Installation & Interconnection for details. For all services, the connection type (fractional or metric) will default to that supplied for the inlet system. Safe Area Systems Dry Gas Vent When the vacuum system shuts down, it automatically vents so that the internal pressure rises up to ambient. Atmospheric air contains water vapour which, if present in the vacuum chamber, will prolong the time to pump down when the vacuum system is restarted. A dry gas vent facility is provided to allow the system to vent with a clean dry gas (most commonly nitrogen), which significantly reduces the time required for the subsequent pump down. Connection is 1/4” / 6 mm compression. Pressure should be in the range 0.5 to 2 bar(g), minimal flow requirement. An onboard filter / regulator reduces the delivered pressure to 0.2 bar(g). Nitrogen supply can be from a cylinder or a plant nitrogen line. Enclosure Purge 3-10 To prevent a build-up of toxic or flammable gases in the enclosure in the event of a sample leak, a facility is provided to purge the enclosure with compressed air. For a system operating with an RMS at an exhaust pressure of 0.2 bar(g), the maximum leakage rate into the enclosure is 0.25 l/min (consult the factory for leakage rates for other inlet types or operating conditions). Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Site Requirements Other Services It is the responsibility of the user to determine the required flow of compressed air for a given leakage rate and to provide a means of monitoring the purge. Instrument quality air must be used – the air supply must be clean and dry. Connection is 1/4” / 6 mm compression. A needle valve is provided inside the unit for flow adjustment. Hazardous Area Systems Warning! For further description of the operation of the following supplies, see Appendix A: Hazardous Area Operation. Dry Gas Vent Use of the dry gas vent facility is a requirement for ATEX/IECEX systems. Warning! For hazardous area systems, the dry gas vent is connected and used in the same way as for safe area systems, but serves an additional function. Filling and pressurizing the analyser with a gas such as nitrogen ensures that hazardous gases cannot enter the vacuum chamber and pumping lines while the system is switched off. On startup there is then no possibility of gas in the analyser volume being ignited (such an ignition could propagate outside the instrument enclosure). Rotary Pump Purge The following is applicable to Zone 1 (ATEX/IECEX) and Div. 1 applications. Warning! Use of the rotary pump purge facility is a requirement for ATEX, IECEx and Div. 1 systems. Thermo Fisher Scientific  To avoid the possibility of an explosive gas mixture igniting during passage through the rotary pump, a nitrogen purge is applied to the ballast port of the pump to suppress oxygen levels below the ignition limit.  A flow of 0.6 Nl/min is required.  This supply is shared with the dry gas vent and hence has the same pressure requirements. Failure of the supply will result in power to the pump being switched off.  If nitrogen is to be supplied from a cylinder, ensure that backups and automatic changeover functions are in place. Prima PRO & Sentinel PRO Mass Spectrometers User Guide 3-11 Site Requirements Other Services Compressed Air Requirements  Where this feature is used, the onboard pressure regulator is set to 0.4 bar(g).  Nitrogen or inert gas must be used. Air is not acceptable. A compressed air supply is required for the following two functions.  Cabinet purge: Requires a continuous flow of 100 Nl/min. Failure of the air supply will result in power to the instrument being cut on all purge options other than z-purge. Reliability of the air supply is therefore critical to ensure uninterrupted operation.  Air conditioner: A continuous flow of up to 300 Nl/min is required to operate the air amplifiers that provide air flow for the air conditioner condenser coil. The compressed air supply must be in the pressure range of 4.0 to 6.9 bar(g). Note:  There is an option for operation at pressures up to 10 bar(g).  The selected option will be indicated on the instrument label. This must be adhered to.  If the pressure is likely to exceed the specified maximum, additional regulation and pressure relief must be installed in the incoming line. The supply must be capable of delivering the total required flow, i.e. 400 Nl/min. Instrument quality air must be used – the air supply must be clean and dry. Filter / regulator units are fitted for each of these functions. These filters should be considered as a final stage backup, not as active devices, and any problems with particulates, water, or oil entering these filters should be rectified upstream of this point. The air inlet connection is 1/2” or 12 mm compression (location shown on the appropriate installation drawing). A single connection point is provided, except where remote or dual RMS systems are involved, in which case there may be two connection points. Note that the required minimum pressure is the pressure delivered to the connection point, at the specified flow rate. Consideration should be given to the pressure in the supply main and pressure drops in the supply line (due to line length and diameter). 3-12 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Site Requirements Options Warning!  Both of the above compressed air supplies vent to atmosphere at the analyser.  Due to the risk of asphyxiation, inert gases such as nitrogen should not be used instead of compressed air. There is no facility in either case to pipe away the spent gas. Options Pump Purge Gas Some, or all, of the following pump purge gas options may have been ordered, depending upon the instrument application. These are normally only necessary for applications involving condensable, corrosive, or toxic sample gases. The purge gas is normally nitrogen, though in some cases instrument air may be acceptable. All connections are 1/4” or 6 mm compression. Rotary Oil Box Purge A rotary oil box purge may be required to ensure a positive flow of purge gas through the rotary pump oil box to dilute and sweep the gases out into the rotary pump exhaust line. The purge gas flow should be controllable up to 1 l/min (by means of an external control valve and flow meter). Rotary Pump Ballast A rotary pump ballast purge primarily prevents formation of liquids from any potentially condensable vapours being pumped, but it also provides a general purge for the pump oil. The purge gas flow should be controllable up to 5 l/min (by means of an external control valve and flow meter). Turbo Pump Bearing Purge A turbo pump bearing purge is used to protect the turbo pump bearing when highly corrosive gases are being pumped. The flow requirement is very low and is internally regulated. Nitrogen is the preferred purge gas in this case. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 3-13 Site Requirements Options External I/O Unit Various options are available to handle I/O that is not available within the main instrument enclosure. Typically, this is for larger quantities of discrete I/O (analogue and / or digital) but may also be used for protocol converters. Such units are generally stand-alone, requiring a mains power supply. The unit can be located remotely from the main instrument enclosure, connecting via a serial link (most commonly RS422). The exception is Ex I/O units, which are local to and powered from the main instrument enclosure. Separate documentation will be provided for this type of unit. 3-14 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Chapter 4 Handling & Storage Receiving the Instrument Note: Thermo Scientific instruments are shipped by carriers who specialize in the handling of precision equipment. In the unlikely event that equipment is inadvertently damaged in transit, follow the instructions below to protect yourself and your company from any possible loss or liability. On receipt, inspect for any obvious damage or evidence of rough handling, including triggering of the shock indicator and tilt labels. If external damage is apparent:  Do not refuse shipment. Instead, make a note of any damage on the receiving documents, and leave the instruments in their original packaging.  Request inspection from the carrier within 15 days of delivery (3 days for international), and contact Thermo Fisher Scientific to report the damage.  Move the cartons to a protected location, preferably the installation site.  Leave the boxes as complete as possible, and do not unpack or open the boxes without a representative from Thermo Fisher present or express instruction to do so by a Thermo Fisher employee. Doing so may void your warranty or order. If there is no visible damage to the packaging the instrument should be unpacked if installation is imminent (see next section “Unpacking the Instrument”). If it is likely that installation will not take place within 8 weeks of receipt, it is recommended that the instrument be left in its original packaging and stored in a protected environment (see “Storing the Instrument”). Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 4-1 Handling & Storage Unpacking the Instrument Unpacking the Instrument The instrument should be unpacked following the directions marked on the packaging itself. Should there be any visible signs of damage to the instrument once removed from its shipping packaging, contact Thermo Fisher with details. It is recommended that any peripherals packed within the crate, or shipped separately, are left sealed in their own packaging until ready for use. Storing the Instrument 4-2 Whether for an extended period or for a period prior to installation, the instrument should be stored in the following manner:  In a secure location.  In original packaging, upright or horizontal.  Dry (protected from standing and falling water, etc.).  Between 5°C and 40°C (40°F and 105°F).  90% maximum humidity, non-condensing.  All packages together. Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Chapter 5 Installation & Interconnection Introduction This section covers the work to be carried out before startup of the instrument. Before continuing, review “Handling & Storage” (Chapter 4). All aspects addressed in Chapter 3: Site Requirements should be in place or provided for before continuing. Note: The instrument must be positioned upright and stationary for at least 24 hours before applying power. Positioning the Instrument The site should meet the environmental specifications detailed in Chapter 3: Site Requirements. The instrument should be positioned to allow service access through the cabinet door, to the inlet system, and to the air conditioning unit. Caution! The instrument should be positioned so as not to obstruct or impede easy access to the isolation switch. Refer to the relevant site installation drawings for detailed information. The instrument is mounted to a frame suitable for floor / wall fixing. See the appropriate installation drawing for details of fixing points and recommended clearances. Cable Connections General Requirements Safe Area Systems Thermo Fisher Scientific A grounded, blank, gland plate is supplied in the enclosure base. This is the only place where drilling the enclosure for user cable entries is allowed. Wherever possible, the outer screen or armour of cable entering at this point should be grounded to the enclosure. Any cable glands compatible with the cable / conduit type being used are acceptable providing that the enclosure integrity is maintained. Prima PRO & Sentinel PRO Mass Spectrometers User Guide 5-1 Installation & Interconnection Cable Connections Hazardous Area Systems Warning! No user electrical connections (power or signal) are made within the instrument enclosure. Any such connection may cause a hazard and will invalidate the hazardous area certification of the instrument. All electrical connections are to be made to the flameproof box above the main enclosure (or to additional flameproof boxes in the case of extended I/O). See Appendix A: Hazardous Area Operation for further details. Warning! Power Connection Safe Area Systems 5-2  If fibre optic communications links have been ordered, the fibre connection point is within the enclosure and is the only situation where cable entry to the purged enclosure is permitted.  To maintain the factory tested enclosure integrity, the cable gland(s) used must be Exe or of metal construction and a minimum IP rating of IP65.  If conduit or loose core cable is used, a seal must be created at the gland to prevent loss of purge gas down the conduit / cable.  The fibre optic cable should pass through the enclosure wall and connect directly to the fibre optic converter within the enclosure.  Do not use bulkhead connections in the gland plate.  The installer should maintain a record of the size of the hole and gland type used so that correct replacements can be provided should this become necessary at any point.  Further details of the fibre optic cable requirements are given in Chapter 3: Site Requirements. Consult Chapter 3: Site Requirements for details of the power supply requirements. The power supply cable must be compatible with the supply current and the relevant local electrical regulations. The mains power cable should be brought into the enclosure via the bottom gland plate. Live (hot) and neutral conductors are to be connected to the isolation switch MAINS IN terminals L1 and L2/N respectively (see Figure 5–1). The earth conductor MUST be attached to the Primary Earth stud adjacent to the isolation switch, identified by the symbol: . Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Installation & Interconnection Cable Connections No other connection may be made to this terminal. Figure 5–1. MAINS IN terminal (safe area system) Hazardous Area Systems Power is connected directly to terminals in the flameproof enclosure (which contains the power isolation device). The entry port in this box is M25 (an adapter to 3/4” NPT is also supplied). Warning! The cable / conduit entry gland used must be Exd certified in order to maintain the flameproof integrity of the enclosure. Incoming cables must be rated for >80˚C. Live (hot) and neutral conductors are to be connected to the MAINS IN terminals labelled 1 and 2 respectively. The earth conductor MUST be attached to the internal or external Primary Earth, identified by the symbol: . No other connection may be made to these terminals. Mains IN Primary Earth (internal) Signal connections Figure 5–2. MAINS IN terminal (hazardous area systems) Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 5-3 Installation & Interconnection Gas Connections Sentinel PRO Sample Pump Power Connection Signal Connection A separate 3-phase supply is normally required for this option. Refer to the manual supplied for the specific pump. Cables used should be compatible with local electrical regulations. Cabling should be kept as short as possible from cable entry to connection point. Cables should be tied down or neatly bundled together and MUST be kept separate from existing electrical and electronic items (including cables) in the enclosure. Cable screens should be terminated at the point of entry. Safe Area Systems All external serial connections are made to the local I/O board in the instrument enclosure. See Figure 5–3. Further details are in Appendix D: Local I/O. Safe area systems may be fitted with optional discrete analogue I/O. Connection are made directly to the individual I/O modules. Hazardous Area Systems Warning!    Gas Connections Signal cables are connected directly to terminals on the isolation PCB in the flameproof enclosure (see Figure 5–2). The entry ports in this enclosure are 5× M20 (adapters to 1/2” NPT are also supplied). The cable / conduit entry gland used must be Exd certified in order to maintain the flameproof integrity of the enclosure. Sample gas, calibration gas, and exhaust gas connections should be made as specified in Chapter 3: Site Requirements. Pipe runs should not restrict service access to the instrument. All gas lines should be leak checked after installation. Where heat tracing of lines is required, this should be fully tested. Other Services Certain options may require additional services (e.g. compressed air, nitrogen). These are specified in Chapter 3: Site Requirements. As stated above, care should be taken with tubing / pipe runs to avoid restricting service access. 5-4 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Installation & Interconnection Computer System Computer System A separate mains power feed is required for the PC. The Prima PRO system is connected to a Windows-based computer running the Thermo Scientific GasWorks software. The host port of the instrument (see Figure 5–3) connects to a serial port on the computer. If necessary, the latter can be provided via a USB-to-serial adapter. Figure 5–3. Serial communication and digital I/O terminal identification for safe area Prima PRO analyser Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 5-5 Chapter 6 Commissioning General Initial startup of the instrument will normally be carried out by a trained engineer and is typically included as part of the purchase contract. The full startup and configuration procedure is detailed and can be complex for some applications. It is therefore recommended that initial startup should not be attempted by the user, unless they have significant experience with the instrument on the specific application. When commissioning is requested, a confirmation of site readiness will be required. This will normally be in the form of the Site Requirements Checklist, which is to be returned to the office organizing the work. The user must complete this form to confirm that the installation site is ready before the engineer will be allowed to travel to site. Procedure The procedure followed by the commissioning engineer will include the following steps. Note: User and or site personnel may be required for some of these steps. The schedule, content, and availability of user and or site personnel should be agreed before work commences. 1. Verification of Site A brief inspection will be carried out to ensure that the site has been prepared and all site services are available in accordance with the site requirements detailed in Chapter 3. 2. Verification of Hardware An inspection of the hardware will be carried out to verify that no visible transit damage has occurred. The delivered hardware will also be checked with the user to verify that it is consistent with the order. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 6-1 Commissioning Procedure 3. Startup The instrument must have been in position, upright and stationary for at least 24 hours before startup. The instrument will be powered up. A number of tests will be carried out to verify that the instrument is working correctly. These tests are the same for all instruments, regardless of application. 4. Application Configuration The software database will be configured for the application and the specific installation. This includes: a. Setting up the analysis method for the gases involved in process mixture(s). b. Configuring the sample streams. c. Setting up the calibration method(s). 5. Application Verification The above configuration will be functionally tested by running a full calibration, followed by analysis of process gas mixtures. Performance testing will be carried out by analyzing a calibration gas (typically the “mixed gas”, which will generally be similar to the process gas in composition) over a period of time. Other standard gas mixtures may also be used if they fall within the concentration limits defined in the performance specification. In some cases, achieving a particular performance during testing on a specific mixture or mixtures will be part of an agreed acceptance criterion. 6. Communications and I/O (where applicable) Communications will be configured and tested. Wherever possible, initial testing will be to a PC running a test program appropriate for the protocol in question (e.g. the installation engineer’s laptop PC or the GasWorks PC). Subsequently, testing of the full link to the DCS will take place. Suitably qualified personnel must be available to check the DCS end of the link. Any discrete I/O will also be configured and tested as above. Suitably qualified personnel must be available to check the DCS end of the link. 6-2 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Commissioning Procedure 7. Training Approximately two days of the commissioning will be allocated to operator training. The schedule, content, and availability of personnel should be agreed before work begins. More detailed training courses are available and should be considered when some experience has been gained with the instrument. For further details and a quotation, contact the local Thermo Fisher Scientific office or representative. 8. Acceptance At the end of a successful startup, unless the contract indicates otherwise, a formal acceptance of the system will be required. A standard Thermo Fisher Scientific acceptance document will be used. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 6-3 Chapter 7 Startup & Shutdown Startup These procedures assume that the system has been installed and commissioned as earlier in this manual. Procedure The startup procedure for the instrument is as follows: 1. Ensure that the rotary pump is filled with oil to a point just below the upper marker on the oil level window. Ensure that the pump outlet is not obstructed. 2. Check that the Main Electrical ISOLATOR is switched OFF: For safe area systems, red / yellow rotary switch on lower left side of cabinet, OFF = HORIZONTAL. For hazardous area systems, red E-Stop switch on left side of top mounted flameproof enclosure pressed in. All the internal circuit breakers should be switched to OFF (breaker to down position). Check that the TURBO RUN toggle switch (middle of the front of the PDU) is in the OFF position (OFF = switch UP!). 3. Apply mains power to the instrument and switch the Mains Electrical ISOLATOR to ON: For safe area systems, red rotary switch ON = VERTICAL. For hazardous area systems, E-Stop switch ON = OUT (rotate to reset, key required). In the case of an Ex system, an initial purge cycle will need to be completed (automatic or manual, depending on area classification) before mains power is switched to the instrument cabinet. 4. Switch the circuit breakers to ON (breaker to UP position): CABINET, INLET, ROTARY 1 (and ROTARY 2, if applicable), and COOLING. 5. Turn the TURBO RUN toggle switch to ON (ON = switch DOWN!). Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 7-1 Startup & Shutdown Procedure 6. At this point, both the rotary and the turbo pumps will operate. 7. Switch on the PC (monitor and printer where applicable). Double-click on the GasWorks icon. GasWorks may have been configured to automatically connect to the instrument CPU (this will have been set by checking connect automatically on startup under GasWorks Session > Preferences > Instrument). If it has not been configured to connect automatically, click on the Connect icon ( ) to connect to the instrument CPU (Figure 7–1). Figure 7–1. Connect to GasWorks The instrument status light in the bottom toolbar will indicate when the instrument vacuum is at the correct level and filament emission is achieved. The instrument status light is an acknowledgeable alarm indicator. It should be GREEN, indicating a “go” condition, where all the measured instrument parameters are within their configured alarm thresholds. If any measured instrument parameter is outside its configured alarm threshold, then the instrument status light will be shown in RED, indicating a “no-go” condition. If the instrument status light is shown UNCOLOURED (GREY), either a complete cycle of instrument parameter measurements has not been completed or the host PC has not connected to the instrument CPU. If the pressure is not below the vacuum gauge trip level then the emission will not switch on and the ion energy will remain at zero. Note that a single mouse click on the Instrument Status toolbar button will open the instrument status window (Figure 7–2), 7-2 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Startup & Shutdown Procedure which shows the alarm status of each of the instrument parameters. Figure 7–2. Instrument Status window A click on a particular parameter status light will show the current value, alarm limits, and alarm acknowledgement button (Figure 7–3). If all parameters are within limits but the status light is red, clicking on the Acknowledge All button will change the instrument status light to green. Wait until all parameters are within limits (the status light is green), before starting scheduled analysis. Figure 7–3. Parameter status window Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 7-3 Startup & Shutdown Procedure Vacuum Gauge Trip Level Before the filament (and ion energy) can be switched on, the pressure in the vacuum chamber must be less than the vacuum gauge high pressure trip level (normally set to 3.2 x 10-5 mbar) and also higher than the vacuum gauge low pressure trip level (1 x 10-7 mbar). On initial switching it is quite normal for the filament to outgas slightly as it heats up. This will result in an increase in the measured pressure of the vacuum system. The trip logic therefore has a limited amount of hysteresis to accommodate the pressure rise. To prevent the trip circuit from immediately switching the filament off again, the “off trip” is set higher than the “on trip” so a pressure reading above the set point is normal. Starting Scheduled Analysis Click on the Traffic Lights button ( ) to start a scheduled analysis. Each enabled stream will be selected according to its sequence, the concentrations measured, and output via data communications to an I/O unit or other host computer. If the numeric display window is selected, the concentrations will be displayed on the host PC monitor (Figure 7–4). Similarly, if a trend display has been configured and is selected, concentration trends with time can be viewed (Figure 7–5). Figure 7–4. Numeric trend window 7-4 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Startup & Shutdown Procedure Figure 7–5. Trend display Checking Instrument Tuning and Mass Alignment For a detailed description of instrument tuning parameters and mass alignment please refer to Chapter 8: Status & Tuning Parameters. Note: Control Centre should not be opened whilst Schedule is running. Before running Control Centre, ensure Schedule is stopped. A single click on the Control Centre button ( ) will open the Control Centre window (Figure 7–6), which has the following tabs: Thermo Fisher Scientific  Emission  Peak shape  Sensitivity  Detectors  Mass alignment  Heaters Prima PRO & Sentinel PRO Mass Spectrometers User Guide 7-5 Startup & Shutdown Procedure Figure 7–6. Control Centre window Each tab groups a set of adjustable instrument parameters and associated system readings. Each adjustable parameter is displayed with a value and slider bar. Each parameter can be adjusted in one of three ways:  By typing in the required setting and pressing Enter.  By clicking on either the left or right arrow to change to a lower or higher setting respectively.  By dragging the position indicator along the adjustment bar. Several tuning regimes can be configured in which different “sets” of tuning settings can be grouped. In practice there is a “default” tuning regime for all masses above a certain cut-off in the range of 5 to 19 and a “low resolution “tuning regime for all masses below this cutoff. Emission Peak Shape 7-6 The first tab is by default Emission. This tab allows the following:  Switching the filament on and off.  Changing the selection of either filament 1 or filament 2.  Adjusting the trap current. The Peak Shape tab displays the ion intensity over a defined mass window (Figure 7–7). Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Startup & Shutdown Procedure Figure 7–7. Peak Shape tab Once a suitable peak has been located, the peak shape (height and width, extent of flat top, and steepness of peak sides) may be optimized by adjusting the following parameters: Sensitivity Thermo Fisher Scientific  Trap Current  Quadrupole Lens  Resolution  Repeller Voltage  Focus Voltage  Deflection Voltage The effect on ion intensity at a selected mass (default mass 28.0) of changing the repeller, focus, deflection and resolution voltages can be viewed on the Sensitivity tab (Figure 7–8). Each parameter can be selected in turn from the Function drop down list, and a graph of peak intensity versus voltage produced. A cursor can be selected, set at the optimum position on the graph, and the associated tuning parameter setting stored using the Set DAC button. Prima PRO & Sentinel PRO Mass Spectrometers User Guide 7-7 Startup & Shutdown Procedure Figure 7–8. Sensitivity tab Detectors The Detectors tab (Figure 7–8) is only available for dual detector systems with both Faraday and Secondary Emission Multiplier (SEM) detectors. As both detectors are off-axis, a deflection voltage is applied to divert the ion beam into the selected detector. Deflector voltage settings for both detectors are optimized on this tab. The SEM voltage can be adjusted (i.e. calibrated) to set a specified gain (typically 103 or 104). Figure 7–9. Detectors tab Mass Alignment 7-8 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Startup & Shutdown Procedure The Mass Alignment tab (Figure 7–10) is used to display peaks over a defined mass range in a similar way to that used on the Peak Shape tab. In this instance, a cursor is used to assign mass numbers to identified peaks. Typically, two or three masses need to be ‘locked’ over the mass range of interest. Figure 7–10. Mass Alignment tab The Prima PRO mass position is related to magnetic field by the following equation mass = km x field2+cm where km is a constant of proportionality and cm is an offset, with both of these constants having a slight mass dependency. Values of km and cm are determined for adjacent pairs of locked masses; at masses beyond the locked mass range, the values of km and cm are taken from the closest locked mass pair. If an incorrect mass assignment is made the mass table can be deleted and the process repeated. Since the Prima PRO instrument is a magnetic sector mass spectrometer, which produces a focused ion beam at the detector, the peak shape obtained is ‘flat-topped’, i.e. uniform response is observed over a finite mass width, e.g. 0.3 amu at mass 28. Provided the measurement taken at the mass of interest is on the peak’s flat top, high precision analysis will be observed. If masses are aligned within the central 2/3 of the flat top region, this is normally sufficient to guard against any drift in the mass scale. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 7-9 Startup & Shutdown Procedure Heaters The Heaters tab (Figure 7–11) allows for adjustment and setting of the source temperature, inlet probe heater power, RMS body temperature, and RMS sample tube temperature. Figure 7–11. Heaters tab Checking Instrument Status Parameters Open the Instrument Status window (see Figure 7–2). The tabs and the readings displayed under each tab are listed below. Analyser tab  Cabinet temperature: Within the range 10°C to 35°C.  Electronics temperature: Within the range 10°C to 45°C.  System pressure: Typically 5 x 10-6 mbar, but application dependent. Refer to installation records for setting of optimum pressure. Source tab  Ion energy: Approximately 1000 V (for 150 amu mass range) or 800 V (for 200 amu mass range).  Electron energy: Typically set to 70 V.  Filament current: Depends on filament type:  2.4-2.9 A for a Thoria coated iridium filament  1.5-2.5 A for a W/ThO coiled filament  3.0- 3.8 A for a Re filament Note If filament is close to zero, check that Trap Current is set to at least 20 µA and EE is at least 50 V. 7-10 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Startup & Shutdown Shutdown  Trap Current: Within the range 10 µA to 100 µA.  Source Current: Within 2 to 15 times the value of Trap Current.  Repeller Voltage: Normally within the range of 0 V to 10 V. Power Tab  Magnet Current: With 1000 V ion energy for any mass, the magnet current is given approximately by 2.3 x (mass/28)0.5. Shutdown Introduction The shutdown procedure will vary slightly depending on application and on what the system is doing at the time of shutdown. In general, it is better to leave the instrument running rather than repeatedly shutting down for periods of inactivity. This is true even if the instrument will be unused for several weeks. However, shutdowns will be required for routine maintenance, etc. The emergency shutdown procedure (later in this chapter) should also be followed in the event of a power failure. Shutdown Procedure The following steps should be carried out in sequence. 1. Shut off all sample gas flows. When the system shuts down, all the heaters will go off and gas handling parts of the system will begin to cool. Where there is a risk of residual sample gases condensing, it is recommended that the inlet system be purged with a suitable inert gas such as nitrogen before power is removed. 2. Switch OFF the filament on the Emission tab of the Control Centre software. 3. Switch the TURBO RUN micro switch to OFF (OFF = switch UP). 4. Disconnect GasWorks software with the icon. 5. Switch OFF the Mains Electrical ISOLATOR (see “Startup” earlier in this chapter) to de-energize the system electronics. Isolate power externally to fully de-energize the system. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 7-11 Startup & Shutdown Shutdown Following is the emergency shutdown procedure. Emergency Shutdown 1. Switch off power, either at the Mains Electrical ISOLATOR (see “Startup” earlier in this chapter) or at an external power isolation device (the latter is equivalent to a power cut or, in the case of an Ex system, the purge controller switching off the power). 2. The system heaters will now be de-energized and gas handling parts of the system will be cooling down. All sample gas flows should be switched off as soon as possible. Where there is a risk that residual sample gases will begin to condense, the inlet system should be purged with a suitable inert gas such as nitrogen as soon as possible. 7-12 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Chapter 8 Status & Tuning Parameters Instrument Status Instrument status and tuning parameter values may be checked by clicking on the Instrument Status button in the GasWorks software. Parameters are grouped under separate tabs according to the following headings from bottom to top:  Source  Analyser  Inlet  Collector  Power  Comms Figure 8–1. Instrument Status window Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 8-1 Status & Tuning Parameters Source Tab Source Tab Electron Energy This supply provides the energy to accelerate electrons (produced by the filament) through to the ion source. Electrons subsequently interact with molecules of the sample gases to create ions, a process referred to as ionization. The electron energy can be adjusted through on the Sensitivity tab of Control Centre; however it is typically set between 40 and 70 V. The main effect of varying the Electron Energy parameter is to vary the types and ratios of ions, the “fragmentation pattern” produced by electron impact of the sample molecules. In addition to dislodging one or more electrons from the sample molecule (to produce singly or multiply charged positive ions), the electron impact can also break molecular bonds to generate smaller fragments. Lower electron energy tends to give a lower abundance of fragment and multiply charged ions, which in certain applications can help reduce the extent of component overlap and therefore analytical complexity. Emission The Emission status is a “composite” status channel that shows when all related parameters are within limits. Filament Current When the emission is switched on, the current through the filament will be approximately 2.4 to 2.8 A when fitted with Thoria filaments. When fitted with non standard Tungsten filaments, the current will be closer to 3.7 A. If the Filament Current value is close to zero, access Control Centre, and check that the Trap Current setting (from Emission tab) is at least 10 µA and the electron energy setting is at least 40 V. Filament Current Limit Filament Current Limit is provided to protect the filament from being overdriven and can be adjusted in Control Centre. The current limits for common filaments are shown in the table below. Table 8–1. Current limits for common filaments 8-2 Filament Current Limit (Amps) Thoriated iridium 3.1 Tungsten / ThO alloy 3.0 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Status & Tuning Parameters Source Tab If the limit is set too low, then the filament may take some time to regulate when it is first switched on, or may fail to emit at all. If the value is too high, then there is a danger that the filament might blow, burn out, due to excess current. When switched on, filaments will run in limit for a short period until the surface attains temperature and the required level of electron emission is reached. Ideally, current limits are set about 0.4 A higher than the normal running current. Filament Integrity Filament integrity will indicate OK when the filament circuit is continuous and Failed when open circuit, normally indicating a filament failure. If maintenance has just been performed on the instrument check that all cable harnesses have been reconnected before assuming a filament failure. Filament selection between filaments 1 and 2 is made in Control Centre from the Emission tab. If the first running filament fails, consideration should be given to scheduling a routine source change. This is particularly important where analytical data is critical and an unscheduled shutdown caused by failure of a second filament could have additional consequences. Half Plate 1 and 2 Output Voltages Two 1/2 plates positioned after the source block are used to focus and steer the ion beam. The potential difference between the two plates represents the deflection voltage and can be varied in the range -100 V to +100 V by adjusting the Deflection Voltage setting on the Peak Shape tab in Control Centre. The mean voltage for the 1/2 plates represents the focus potential and can be varied in the range 0 V to 960 V by adjusting the Focus Voltage on the Peak Shape tab in Control Centre. In Current Limit In Current Limit indicates that the filament current is in limit and that emission control is not yet established. This is normal for a few seconds while the filament heats up after switching on. OK indicates that emission control has been attained and the filament is NOT in current limit. Ion Energy Thermo Fisher Scientific This supply provides the energy to accelerate the ionized sample molecules out of the source and into the magnetic field where they will separate according to their respective mass / charge ratio. The Ion Energy value is nominally 1000 V for 150 amu mass range Prima PRO & Sentinel PRO Mass Spectrometers User Guide 8-3 Status & Tuning Parameters Source Tab instruments and is set in on the Mass Alignment tab of Control Centre. A lower voltage setting will achieve a higher mass range as the mass range is inversely proportional to ion energy. See Appendix B: Technical Description: for more detail. The mass range is therefore about 200 amu at an ion energy setting of 750 V. Note All the tuning parameters need to be re-optimized and mass scale recalibrated if the ion energy setting is changed. Repeller Voltage Source Current The ion repeller is an electrode within the source block that ensures ions move towards the ionization chamber exit slit. The voltage applied to this plate affects sensitivity and may influence the peak shape, linearity, and stability. The voltage applied to the ion repeller is usually in the range 2 to 10 V, although it can be adjusted over the range -10 V to +20 V. The Source Current parameter represents the electrons emitted by the filament that do not traverse the source to be collected at the trap electrode. The proportion of the electrons traversing the source to the trap electrode normally results in a source current 2 to 5 times greater than that of the trap. A source current ten times or greater than that of the trap suggests that the filament may either be poorly aligned, have become distorted, or the ion source has become contaminated, affecting the number of electrons which can reach the trap. Stability and linearity tend to be worse at higher source current / trap current ratios. 8-4 Source Temperature The ion source is heated by a cartridge heater in the ion source block, and temperature is monitored by a platinum resistance thermometer (PRT). Source temperature is normally set within the range of 140°C to 200°C on the Heaters tab of Control Centre but can be application dependant. Limits will be set accordingly. Trap Current The trap electrode is used to regulate and control the electron emission through a control loop to the filament current drive. Increasing this parameter will increase sensitivity, but care must be taken to ensure that the biggest peaks can still be measured on the lowest amplifier gain range. As a guide, mass 28 should not be much set greater than 7 x 10-10 A Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Status & Tuning Parameters Analyser Tab with air in the inlet. This is usually achieved with trap currents in the range 20 µA to 100 µA. Analyser Tab ASU Controller Status A value of 1 in the ASU (analyser supplies unit) Controller Status field indicates the ASU to be operating within normal limits. Other status conditions are as follows. Table 8–1. ASU Controller Status conditions Status Value No Communications -1 Uninitialised 0 OK 1 Flashover Detected 3 Power Supply Low 4 Cabinet Temperature The temperature in the cabinet is monitored by a sensor located near the turbo molecular pump and should read less than 35°C. Electronics Temperature The temperature in the electronics is monitored by a sensor and should read less than 50°C. Magnet Controller Status A value of 1 in the Magnet Controller Status field indicates this unit is operating within normal limits. Other status conditions are as follows. Table 8–2. Magnet Controller Status conditions Thermo Fisher Scientific Status Value No communications -1 Magnet out of control 0 Until first initialisation after power up. Magnet in control 1 Ready for use. Magnet out of range 2 Last request was out of range. Magnet not available 3 Unknown. Magnet zero required 4 Requires initialisation. Magnet field busy 5 Settling last requested field. Magnet frequency busy 6 Integrating VFC. Magnet zeroing busy 7 Zeroing the sense coil. Prima PRO & Sentinel PRO Mass Spectrometers User Guide 8-5 Status & Tuning Parameters Analyser Tab Mass Filter Status Value Magnet temp busy 8 Measuring the magnet temperature. Magnet failure 9 Controller or circuit failure. Magnet pulse busy 10 Busy driving the magnet. Magnet field init busy 11 Initialising the system (about 60 s) The approximate magnetic field setting, in Tesla, is indicated by the Mass Filter parameter. The value for Mass 28 with 1000 V ion energy is typically 0.4 Tesla. The relationship between mass and magnetic field and ion energy is given by: Mass  (magnetic field)2 /ion energy A four times increase in magnetic field strength therefore doubles the mass detected. Pressure Set Point System Pressure At pressures above the value set in the Pressure Set Point parameter, power is removed from the filament supply, source heater, SEM supply, and source high voltage supplies to protect the analyser from damage which may result if run at high pressure. The System Pressure value indicates the pressure as reported by a Penning vacuum gauge head that is mounted on the top right of the vacuum chamber and is a measure of the high vacuum produced by the turbo molecular pump. The pressure, as measured by the Penning gauge, is a combination of the amount of sample gas leaking into the chamber via the capillary / leak arrangement and gas that ‘evolves’ from the internal surfaces of the vacuum system. This is known as out-gassing. When the inlet is blocked, the vacuum falls to its background level, which is usually in the region of 10-7 mbar. When the inlet is open, the operating vacuum should be in the region of 1 - 10 x 10-6 mbar. This varies slightly from instrument to instrument and on the gas being sampled. The upper limit of pressure that can be displayed by the Penning gauge is about 1 x 10-2 mbar. A stable reading at this level indicates that the pressure may be too high to be measured by the gauge and that there is either a significant system leak or a pumping fault. Check that the turbo molecular pump is up to speed (indicated as Turbo Revs on the Instrument Status window). Check that the rotary pump is functioning correctly. 8-6 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Status & Tuning Parameters Analyser Tab Note that it is detrimental to the gauge to leave it running for an extended period (e.g. more than a few hours) while measuring pressures greater than 10-3 mbar. Excessive ion burns on the gauge will occur, resulting in reduced gauge accuracy. This can only be recovered by cleaning the gauge electrodes. Ions are produced as a result of a discharge formed in the high voltage field between the anode and cathode of the gauge head. As the pressure in the system falls, the number of ions in the discharge reduces and this can be directly associated with the pressure of the chamber. The analyser is protected from damage due to excess pressure by two trip points based on the Penning gauge reading. The Penning gauge gives a voltage output related to the pressure reading according to: p = 10U-10.5 Alternatively, the pressure / signal relationship can be expressed as U = 10.5 + log10P The high pressure trip (see “Pressure Set Point” earlier in this chapter) prevents operation of the emission circuit, ion energy, multiplier, and source heater as described above. A low pressure trip protects the same devices and is a level indicative of a potential gauge failure. The threshold values for these two trips are equivalent to: High Pressure Trip = 3 x 10-5 mbar (approximately) Low Pressure Trip = 1 x 10-7 mbar (approximately) Hysteresis is built into the high pressure trip to allow for the pressure rise that occurs when the filament begins to heat and outgas. System Pressure Trip Turbo Motor Current Turbo Operating Hours Turbo Speed Thermo Fisher Scientific System Pressure Trip will indicate OK if the system pressure is below the Pressure Set Point and Fail if the system pressure is above the Pressure Set Point. The Turbo Motor Current is the current drawn by the turbo molecular pump motor. The Turbo Operating Hours field indicates the running hours for the turbo molecular pump. See the pump manufacturer’s recommendations on service intervals. Turbo Speed is the speed as a percentage of full speed of rotation. 100% is full speed. Prima PRO & Sentinel PRO Mass Spectrometers User Guide 8-7 Status & Tuning Parameters Inlet Turbo Speed Interlock Vacuum Vent Valve OK is indicated in the Turbo Speed Interlock field when the turbo molecular is at speed and under normal operation. OK is indicated in the Vacuum field when the system has reached normal operating levels. Off is indicated in the Vent Valve field when the turbo molecular in under normal operation. Inlet Pressure Raw Pressure Raw is the raw output from the inlet differential pressure transducer and flow sensor as a DAC reading. This is fitted to RMS and solenoid assemblies only. RMS Ambient Temperature The RMS Ambient Temperature is the temperature recorded on the inlet controller electronics. It is typically approximately 45°C. RMS Body Temp RMS Controller Status RMS Sample Flow Sensor RMS Flow Zero 8-8 The RMS Body Temperature as monitored by thermocouple in the RMS block is normally set in the range of 50 to 120°C depending on the application. The RMS Controller Status indicates a value of 1 when the unit is operating within normal limits. The RMS Sample Flow Sensor is the calibrated output of the inlet flow sensor (differential pressure transducer). It is displayed in cc per minute. The RMS Flow Zero is the zero flow output from the analogue flow sensor. RMS Position The RMS Position is the RMS rotary arm position. Sample Tube Current The RMS Sample Tube Current is the RMS sample tube heater current. Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Status & Tuning Parameters Collector Tab Sample Tube Temperature The RMS Sample Tube Temperature is the RMS sample tube heater temperature set point and control. Collector Tab Faraday Deflector The Faraday Deflector parameter is the voltage applied to the deflector electrode that directs the ion beam into the Faraday collector. The Faraday detector is mounted off-axis on both Faraday only and Faraday / SEM dual detector systems. Multiplier Deflector The Multiple Deflector parameter is the voltage applied to the deflector that directs the ion beam into the SEM. This is an optional micro channel plate (MCP) used to increase the dynamic range of the instrument to permit measurement of species at low (ppm and lower) concentrations. Multiplier Voltage The Multiplier Voltage controls the gain of the SEM (Prima PRO analyser uses an MCP). Varying the voltage output can vary the gain of this detector from x10 to approximately x10000. Typically, the gain is set to 2000 for a standard single MCP SEM and 10000 for a dual MCP SEM. Negative and Positive Quad Lens Voltages In conventional sector mass spectrometers, compensation for errors in analyser geometry, magnet fringing field effects, and beam aberrations, resulting from localized, contamination induced charge effects, is achieved with difficulty by adjusting the magnet position. The Prima PRO analyser overcomes this by fixing the position of the magnet and providing a quadrupole lens (quad lens) to compensate for and adjust the position of the refocused beam image. A complicated impractical series of magnet adjustments is therefore replaced with a single voltage adjustment of the quad lens. The quad lens DAC voltage can be varied from -25 V to +25 V but, in practice, a variation of a few volts positive or negative is usually sufficient to achieve a symmetrical, flat-topped peak that provides good, long-term precision from the analyser. Resolution Thermo Fisher Scientific The Resolution Deflector electrode provides Z plane deflection of the ion beam through one of two available resolving slits. The Prima PRO & Sentinel PRO Mass Spectrometers User Guide 8-9 Status & Tuning Parameters Power electrode is part of the detector assembly and is positioned between the quad lens and the detector. The use of two resolving slits permits the selection of a very wide resolving slit when low mass peaks are being measured. This feature results in the production of broad, flat-topped peaks all the way down to mass 1. In conventional mass spectrometers, the resolving slit size is chosen so as to resolve adjacent peaks at the high mass end of the scale (peaks get closer together with increasing mass). The disadvantage to having high resolution is that low mass hydrogen and helium peaks become very narrow and therefore prone to drift when these peaks are to be measured. The high resolution slit is on-axis and for peaks above the switching point, normally greater than mass 5, the voltage for the resolution deflector will be close to zero. Below the switch point, the voltage will be around 250 V, for systems with 1000 V ion energy, deflecting the beam through the broader low resolution slit. Note: On the Sentinel PRO analyser, a different combination of collector slits is used, and the switching point is typically set to mass 100. At lower masses the nominal resolution is approximately 85 and at higher masses the nominal resolution approximately 135. Power Amplifier +24V The Amplifier +24V parameter is the 24 V PDU output for the amplifier. Analyser Supplies +24V The Analyser Supplies +24V parameter is the 24 V PDU output analyser electronics (ASU). Instrument CPU 24V The Instrument CPU 24V parameter is the 24 V PDU output for the CPU card. Fan 24V The Fan 24V parameter is the 24 V power PDU output for the air conditioner condenser fan (safe area only). Failure can also indicate an alarm condition within the A/C. Inlet Probe Current 8-10 The Inlet Probe Current parameter is the current through the inlet probe cartridge heater. Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Status & Tuning Parameters Communications Magnet Supply Current Current passing through the electromagnet coils can be used to give an approximate indication of the current mass number. The approximate current to mass relationship is 4 [I2] for systems with 1000 V ion energy. Mass 100 therefore requires roughly 5 A through the coils. This relationship is very approximate. If the mass table has not yet been generated (or has been corrupted), this relationship can be used to check whether or not the magnet controls circuitry is operating. Magnet Sync AC The Magnet Sync AC parameter is an AC power synchronization signal to the magnet driver card, which improves precision and reduces mains frequency induced noise. Power Controller Status The Power Controller Status parameter indicates a value of 1 when unit is operating within normal limits. Turbo 24V User IO 24V Vent Valve 24V The Turbo 24V parameter is the 24 V PDU output for the turbo molecular pump drive electronics. The User IO 24V parameter is the 24 V PDU output for the user I/O. The Vent Valve 24V parameter is the 24 V PDU power supply for the turbo molecular pump vent valve. Communications Host Comms Quiet The Host Comms Quiet parameter checks for a break in communications between the host PC and the Prima PRO analyser. User I/O 0 Comms Quiet If configured (within GasWorks Hardware Configuration), the User I/O 0 Comms Quiet status is checking for a break in communications between the user I/O card port 0 and a user device. User I/O 1 Comms Quiet If configured (within GasWorks Hardware Configuration), the User I/O 1 Comms Quiet status is checking for a break in communications between the user I/O card I/O 1 port and a user device. User I/O 2 Comms Quiet If configured (within GasWorks Hardware Configuration), the User I/O 2 Comms Quiet status is checking for a break in communications between the user I/O card I/O 2 port and a user device. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 8-11 Status & Tuning Parameters Checking Mass Alignment User I/O 3 Comms Quiet VGiNet Checking Mass Alignment If configured (within GasWorks Hardware Configuration), the User I/O 3 Comms Quiet status is checking for a break in communications between the user I/O card I/O 3 port and a user device. The VGiNet status checks for breaks in the internal VGiNet communications. Use this procedure to check that peaks are being produced and that they are correctly identified and aligned with the mass scale. e.g. Mass 28 for N2 in Air On the GasWorks toolbar click the icon to open Control Centre. If the system has not been tuned previously, use the Peak Shape and Sensitivity tabs to do so. Type in the required value for each parameter and press Enter to set the parameters as follows:  Trap current = 20  Quad lens = 0  Resolution DAC = 0  Repeller Voltage = 5  Focus Voltage = 450  Deflection Voltage: = 0 Select Mass Alignment. Set the Start and End masses (typically beginning with start mass 0, end mass 50), mass Increment (e.g. 0.03), Integration (e.g. 10), measurement Range (e.g. 10), and inlet Stream (e.g. air or N2) parameters. Click on the Start Scan button. Check that peaks are produced and that they are correctly aligned with the mass scale markers. Figure 8–2. Mass Alignment tab 8-12 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Status & Tuning Parameters Checking Mass Alignment To display minor peaks, increase the gain range by clicking on the down arrow button next to the intensity axis. For an air sample, the principle peak will be at mass 28 due to 78.08% of nitrogen (N2 = 2 x 14, where 14 is the atomic weight of nitrogen), and the second biggest peak will be at mass 32 (oxygen at 20.95% O2 = 2 x 16). There should also be a peak at mass 14; this is produced by both atomic nitrogen (N)+ and doubly-charged nitrogen ions (N2)++. The mass spectrometer separates the sample ions according to their mass / charge ratios and some molecular fragmentation occurs in the ion source together with ionization of the gas molecules. Further peaks of interest include 16, 17, and 18 (due to O+ from oxygen and water, OH+ and H2O+ from water), 40 (0.94% Argon), and 44 (350 ppm CO2 12 + 2 x 16). If alignment is poor, the simplest approach is to delete the locked peak table by stopping the scan and clicking on the Delete Locked Peak Table button: . To create a new mass table, add a cursor to the display using the following button: . Position the cursor on mass 14 peak and lock this as mass 14.00. Click the Peak Lock button: . Enter 14.00 in the Peak Locking dialogue box (Figure 8–3). Figure 8–3. Peak Locking dialogue box The value shown in the marked peak window is the Cursor position. Reposition the scan to mass 44 by changing the scan start and stop values and lock this peak to mass 44.00 as before. The zoom-in facility can greatly facilitate accurate mass setting. If a gas (or gases) other than air are used, knowledge of its composition will be needed to correctly identify which peaks are which masses. The approach is as above and should use two or three masses which span the required analysis range. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 8-13 Status & Tuning Parameters Checking Mass Alignment For example, in an ethylene cracker application it is necessary to align the peaks only at masses 2 (H2) and 78 (C6H6) to give accurate mass alignment throughout the 2 to 100 amu mass range. 8-14 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Chapter 9 Fault Diagnosis Introduction Alarm Conditions This chapter provides information on basic fault diagnosis that should only be undertaken by an experienced technician trained in the maintenance of high voltage electronic equipment. The information provided is not exhaustive, and normal diagnostic procedures should be followed where specific details are not given. The status of the instrument is indicated in GasWorks software by the status window display. Any out of limit condition for any parameter is indicated by an alarm condition (normally indicated in red). Typical values, limits, and causes of alarm conditions are indicated in the table below. Table 9–1. Diagnosing alarm conditions Device Typical Reading Set Point Low Set Point High Typical Cause Electron Energy 70.10 volts 30.00 volts 95.00 volts ASU failure Emission 1 0.5 1.5 Power parameters in alarm Filament Current 2.60 amps 1.50 amps 3.50 amps Still pumping down or filament failure Filament Current Limit 3.06 amps Filament Integrity (OK) Half Plate 1 Output Voltage 448.0 volts 300.0 volts 950.0 volts ASU failure Half Plate 2 Output Voltage 431.0 volts 300.0 volts 950.0 volts ASU failure In Current Limit (OK) (OK) Ion source fault Ion Energy 998.0 volts 750.0 volts 1050.0 volts ASU failure Repeller Voltage 6.96 volts -10.00 volts 10.00 volts ASU failure Source Current 85.0 µamps 1000.0 µamps Faulty filament Source Temperature 140.1°C 138.0°C 142.0°C Still warming up or source heater failure Trap Current 29.9 µamps 10.0 µamps 100.0 µamps Filament failure Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 9-1 Fault Diagnosis Alarm Conditions 9-2 Device Typical Reading Set Point Low Set Point High Typical Cause ASU Controller Status 1 0.5 1.5 ASU failure Cabinet Temperature 24.00°C 10.00°C 35.00°C AC fault or AC fan failed / blocked Electronics Temperature 28.20°C 10.00°C 55.00°C Ambient temperature or cabinet filter blocked Magnet Controller Status 1 0.5 7 Magnet busy or failure Mass Filter 0.45690 Tesla Pressure Set Point 3.44e-05 mbar System Pressure 3.13e-06 mbar 2.00e-07 mbar 2.50e-05 mbar Still pumping or leak or pump failure System Pressure Trip (OK) (OK) Still pumping or leak or pump failure Turbo Disable (Off) (Off) Turbo switched to “stop” on PDC Turbo Motor Current 0.62 amps 4.00 amps Turbo adjustment or failure Turbo Operating Hours 7264 hours Turbo Speed 100% Turbo Speed Interlock (OK) Vacuum (OK) Vent Valve Off (Off) RMS Body Temp 59°C RMS Ambient Temperature 42°C RMS Controller Status 1 RMS Digital Input 2 (Fail) RMS Digital Input 3 (Fail) RMS H1 Current 245.0 mA 50.0 mA Heater failure RMS Sample Tube Current 350.0 mA 50.0 mA Heater failure RMS Flow Sensor (OK) RMS Position 31 0.01 amps 95% Still pumping or leak or pump failure Still pumping or leak or pump failure (OK) Still pumping or leak or pump failure 30°C 100°C Still heating up or heater failure 0.5 1.5 RMS electronics failure (OK) 0.5 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Low sample flow Optical sensor / detector needs cleaning Thermo Fisher Scientific Fault Diagnosis Alarm Conditions Device Typical Reading Set Point Low Set Point High Typical Cause Faraday Deflection 559.0 volts Multiplier Deflection 0.0 volts Multiplier Voltage 828.0 volts Negative Quad Lens Voltage -5.38 volts Positive Quad Lens Voltage 5.33 volts Resolution 0.0 volts Amplifier +24V 14.9 volts 14.0 volts 16.0 volts PDC or switch mode ps Analyser Supplies 24V 23.9 volts 22.5 volts 25.5 volts PDC (fuse) or switch mode ps Fans 24V 24.0 volts 22.5 volts 25.5 volts PDC (fuse) or switch mode ps Instrument CPU 5V 4.8 volts 4.8 volts 5.3 volts PDC (fuse) or switch mode ps Magnet AC 38.8 volts 12.0 volts 50.0 volts PDC or switch mode ps Magnet Current 2.84 amps 0.10 amps 10.00 amps Magnet drive or magnet controller Power Controller State 1 0.5 1.5 PDC or switch mode ps Turbo 24V 24.2 volts 22.5 volts 25.5 volts PDC (fuse) or switch mode ps User IO 24V 24.2 volts 22.5 volts 25.5 volts PDC or switch mode ps Vent Valve 24V 24.1 volts 22.5 volts 25.5 volts PDC or switch mode ps Host Comms Quiet 0 seconds User I/O 0 Comms Quiet 0 seconds 300 seconds Turbo controller User I/O 1 Comms Quiet 0 seconds User I/O 2 Comms Quiet 0 seconds User I/O 3 Comms Quiet 0 seconds VGiNet / Opto22 Comms Quiet 0 seconds 20 seconds Cable fault Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 9-3 Fault Diagnosis Leak Detection Leak Detection Warning! High Voltages! To avoid flash over, exercise extreme caution when probing with helium in the vicinity of the ion source feed through. Helium is extremely susceptible to “break down” when exposed to high electric fields.  Abnormally high atmospheric peaks and a slight rise in the background pressure, as displayed by the Penning gauge reading, may indicate a small leak in the instrument. In general, the most convenient method for leak detection is to use the extreme sensitivity of the instrument itself. Tune the mass spectrometer to a suitable gas (helium, mass 4, is particularly effective). Then probe around the vacuum chamber using a fine collimated stream of the same gas. A sharp increase in the ion current of the monitored peak indicates that the search gas has entered the vacuum system. Finer gas flows may be required to help pinpoint the exact location of the leak. Leaks may sometimes occur at elastomer seals, particularly after they have been disturbed. First check that the seal fixings are not loose. If they are, tightening may cure the problem; however, care should be taken not to over tighten as damage to the seal or fixings may result. In most instances, this is due to contamination of the sealing surface by dust, other particulates, or fibres. These can normally be removed by use of a clean, filtered compressed gas or wiping the surface with a clean, lint free cloth. A small amount of solvent, such as IPA, applied to the cloth may assist in the process. A larger leak which results in a pressure rise above 3 x 10-5 mbar will cause the emission to trip or prevent the system from attaining the trip pressure on pumping down from atmosphere. This would prevent switch on of the mass spectrometer. In this case, the leak can potentially be located by probing around the vacuum system with helium and looking for slight changes in the Penning gauge reading. 9-4 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Fault Diagnosis Mass Spectrometer Faults Mass Spectrometer Faults The complete loss of mass peaks or a loss of resolution / peak shape or sensitivity indicates the majority of faults. The following sections are a list of possible causes of the above conditions. Warning! High Voltages! Voltages of up to 1 kV are present! Exercise extreme caution at all times.  No Peaks Thermo Fisher Scientific If there are no mass peaks, complete the following:  Check that the electronics are powered and that all leads are connected and that all fuses are intact.  Check the Instrument Status light is green.  Check for satisfactory electron emission, filament current, source current, trap current, and electron energy on the GasWorks Status Window. If filament is short circuit the filament current will be at filament limit with no trap current.  In Control Centre, set the Ion Energy and Focus Voltages to zero. Disconnect the socket from the source flange plug.  Check each pin on the source flange plug to all others and earth (see Figure 9–1). Continuity should only be found between:  7 and 12 Filament 1  4 and 8 Filament 2  9 and 16 PRT  10 and 11 Source Heater  A plate in the source or collector assemblies may be disconnected and / or charging up. This can only be confirmed by examining the individual assemblies, which requires a full instrument shutdown and removal of the assemblies from the vacuum chamber.  Access the GasWorks Instrument Status window and check that the magnet current is approximately 2.5 amps with mass 28 selected in Control Centre.  If the noise displayed on the computer screen does not increase as the gain is increased, it is likely that the detector system is inoperative. Prima PRO & Sentinel PRO Mass Spectrometers User Guide 9-5 Fault Diagnosis Mass Spectrometer Faults Poor Sensitivity Poor Stability on Startup For low or unstable sensitivity and / or poor peak shape:  Ensure that the source and lens tuning is optimized.  Check for contamination of the source or lens. If necessary, remove and clean.  Ensure that an electrode in the source or collector assembly is not disconnected and / or charging up. Normally, in this condition, no peaks are observed.  Try the second filament. Sensitivity can be degraded after a filament has been in use for a long period, often due to contamination or physical movement of the filament wire.  Check that the Penning gauge pressure reading is normal. An extremely low pressure may indicate blockage of the inlet – blocked RMS and / or screen filter and / or capillary and / or glass leak. There are a number of factors that influence the initial stabilization (settling) of the mass spectrometer following startup or restart. Filament emission characteristics are altered by reactions with the sample gas and depend on the specific chemistry of the gas. Different gas mixtures will have differing effects on the filament. Gas mixtures that have a net oxidizing effect tend to be the reverse of mixtures that are net reducing. Where an instrument has either been idle or analyzing a radically different sample stream, there will be an initial stabilization in the filament characteristics as they adjust to the average composition of the samples. This will normally result in an overall general drift in absolute peak heights. From cold startup, there will be other factors contributing to this effect such as outgassing from the enclosure and various system elements as they come up to working temperature. If there is a very large change in the average gas composition with time, for example from one day to the next, then it may be necessary to recalibrate on a daily basis to maintain system accuracy within an acceptable bandwidth. Most processes, however, involve a stable average composition of process gas samples. Reactions between the sample gases and filament result in changes in the electron work function of the filament emissive material. The electron flux through the ionization region is regulated by control of the trap current, which will adjust filament current to affect any necessary compensation. This in turn changes the filament temperature and could affect the temperature distribution of the ion source, even though the overall source temperature may be regulated to ± 0.1°C by a source temperature controller. 9-6 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Fault Diagnosis Mass Spectrometer Faults There can also be changes to the spatial distribution of electron trajectories and in the electron energies following impact with the sample gas molecules. The nature and efficiency of ionization, as well as the energies and trajectories of ions exiting the source, can all be affected. As a result of all these effects, there can be changes in the absolute sensitivities, relative sensitivities, and cracking patterns. The magnitude of the effects depends very much on the types of gases being analyzed –the more overlaps or the greater the variation in ion types (e.g. mass and multiplicity of charges) the greater the potential impact. Contamination can result in sample reacting with or being absorbed on the walls of the ionization chamber, which can modify the surface potentials due to localized charging effects. Poor Results Following Calibration Check the calibration method has been correctly configured. The general “rules” for configuring calibration gases are as follows: Fragmentation: Can only be selected when there are no overlaps in the spectra of the gas component, at the selected masses, with those of any other gas in the cylinder. Background: Enable for background measurement only when there are no contributions at any of the selected peaks in the cracking pattern for the gas component in the calibration cylinder. Sensitivity: Can be calibrated only when there are no overlaps at the principle peak. Linearity: Can always be calibrated provided the component is present at a significant and accurately known level in a gas mixture. Check that there is flow when the calibration gases are selected. If a non-hazardous calibration gas is selected and no hazardous sample gases are flowing through the RMS, removal of the RMS cover allows for verification that the RMS is selecting the correct calibration gas stream. Check that the Penning pressure reading is consistent with that obtained during original installation. Depending on the molecular leak type used, the Penning pressures for nitrogen or air are typically: 70 micron pinhole leak ca. 5 x 10-6 mbar 50 micron pinhole leak ca. 3 x 10-6 mbar 30 micron pinhole leak ca. 1 x 10-6 mbar Note these pressure readings are gas dependent. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 9-7 Fault Diagnosis Filament Failure A good test for system integrity is to introduce helium, which will typically give the following pressure readings: 70 micron pinhole leak ca. 2 x 10-6 mbar 50 micron pinhole leak ca. 1 x 10-6 mbar 30 micron pinhole leak ca. 5 x 10-7 mbar The above is only a rough guide but can be used to establish if the micro capillary is blocked, significantly lower readings, or there is a gross leak, significantly higher readings. If the capillary is blocked or the ion source is contaminated, the linearity factors obtained during calibration will depart greatly from unity; typically they are close to 1 (e.g. 0.7 to 1.3) but in the event of a blockage or contamination, could be as low as 0.3 or as high as 3.0. Ion Source and Magnet Pole Pieces Assembly Filament Failure After prolonged operation of the unit (typically between six months and two years) a build-up of contamination may occur on the ion source electrodes, the magnet pole pieces, and Z-restrictor. This can result in the build-up of insulating films on metal surfaces, which in turn can charge up and disturb the local field potentials. This usually results in a reduction in sensitivity and / or a distorted peak shape. In this event, it will be necessary to clean the source, pole pieces, and the Z-restrictor. Refer to Chapter 10: Maintenance for cleaning procedures. Typical filament lifetime is six months to two years. The instrument status flags indicate filament failure. Filament current, trap current, and source current will all be zero. Filament failure can be checked (after setting the ion energy and focus voltages to zero), by testing the source flange plug for continuity between pins 7 and 9 for the case of filament 1 or pins 16 and 17 for the case of filament 2 on the source plug. However, since the source is the dual filament type then, provided one filament is still intact, one can simply switch operation to the other filament. Filament replacement can then be carried out at any convenient time, such as during a routine preventive maintenance service. Note: The filament current will be switched off if the Penning pressure rises above its set point. This should be checked before dismantling the system to change the filament.  9-8 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Fault Diagnosis Filament Failure Figure 9–1. Source plug pinout (external feed-through) Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 9-9 Chapter 10 Maintenance Caution! Before commencing any maintenance work on this instrument, refer to instructions in Chapter 2: Safety Information.  Maintenance Schedule The maintenance schedule is summarized in the table below. Table 10–1. Maintenance schedule Frequency* Item Task Weekly Rotary pumps Check oil level, and replenish if necessary. Monthly Air conditioner Check external air circulation, and clean as required. Every 6 months Rotary pumps Change oil. Every 3 years Turbo molecular pump Service pump. * May vary depending on application and environment. Caution! Additional maintenance is required for Ex systems with purge equipment. Refer to additional documentation. Procedures Rotary Pump Oil Level Warning! Hazardous Substance! Thermo Fisher Scientific  Pump oil must not be ingested.  Protective clothing must be worn when replenishing the oil in the rotary pumps.  Keep away from skin, especially open wounds. Pump oil is a possible irritant.  Waste oil is to be disposed of in an environmentally responsible manner. Prima PRO & Sentinel PRO Mass Spectrometers User Guide 10-1 Maintenance Procedures Warning! High Temperatures!  Rotary pumps run hot during operation.  Allow pumps to cool before draining oil. The oil level in the rotary pump should be checked in accordance with the maintenance schedule and replenished if necessary. If a significant loss of oil has occurred, this should be investigated according to instructions provided by the pump manufacturer (manual supplied). Routine oil changes are not required for rotary pumps filled with Fomblin oil. Drain plug Figure 10–1. Rotary pump drain plug Cleaning the Cooling Fans To maintain adequate cooling of the instrument, ensure that the fan covers, air intake, and condenser coil are free of dust. Clean as required. Fan cover guard Figure 10–2. Fan cover guard 10-2 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Maintenance Dismantling and Cleaning Procedures Lubricating the Turbo Molecular Pump Warning! Lethal Voltages! Lethal voltages are present in the vicinity of the turbo molecular pump. Isolate the mains electrical supply before attempting any maintenance activity on the pump.  Maintenance procedures for the turbo molecular pump are given in the instructions provided by the pump manufacturer (manuals supplied). The procedures are quite involved and, in general, it is preferable to return the pump for maintenance. Dismantling and Cleaning Procedures Warning! Lethal Voltages! Lethal voltages are present within the Prima PRO enclosure. Isolate the mains electrical supply before attempting any maintenance activity on the pump.  Filament Warning! Hazardous Substance!  The filament contains hazardous substances and must not be ingested.  Protective clothing (gloves) must be worn when handling the filament. Note: All parts are clean assemblies and gloves should be worn during the following procedure. To remove the filament, proceed as follows. 1. Using Control Centre, switch off the filament. 2. Switch off the electrical power. Wait approximately five minutes for the turbo molecular pump to slow down and vent the system to atmospheric pressure. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 10-3 Maintenance Dismantling and Cleaning Procedures 3. Remove the source connector and 4 x M6 nuts shown in Figure 10–3. Source connector 4 x M6 nuts that secure the source flange to the source housing. Figure 10–3. Removing the source connector and 4 x M6 nuts 4. Carefully lift the source flange complete from the analyser chamber. 5. Remove the 3 x M3 cap heads that secure the source connection ring in the analyser housing and carefully withdraw the source. Note: The filaments are positioned against a “stop” on one side and are “hooked” over the anodized aluminium insulating plates. They are secured by slotted knurled nuts. The filament supply and trap leads are connected to the filament assembly pins by gold socket connectors. Note the position of the three connectors. 6. Remove the socket connectors from the failed filament assembly and the knurled nut. See Figure 10–4. Socket connectors Knurled nut Figure 10–4. Removing the failed filament 7. Using tweezers, withdraw the filament. 10-4 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Maintenance Dismantling and Cleaning Procedures Note: The anodized aluminium insulating plate is left in place. This must be reused or replaced when replacing the filament.  To replace the filament, proceed as follows. 1. Position the filament as shown in Figure 10–4 and fix in place with the knurled nut. Note: The alignment of the filament in the plane of the ion beam is preset. 2. Reconnect the supply leads (socket connectors shown in Figure 10– 4). 3. Check the filament connections for continuity. 4. Check the filament to ion source and trap to ion source and ensure these are open circuit (> 50 M). 5. Refit the source connection ring in the analyser housing and secure with 3 x M3 cap head screws. A dowel pin in the analyser housing ensures the correct orientation. 6. Refit the source flange and tighten the M6 nuts evenly. Ion Source Caution!  This operation should only be undertaken by trained personnel with knowledge of the requirements for the cleanliness of vacuum components.  This operation should ONLY be performed in a dust free, clean environment. Failure to observe this requirement could result in contamination of the assembly with particulates, and / or materials, which could degrade or prevent subsequent operation of the source.  Magnetic particulates will easily attach to the collimating magnets and will be very difficult to remove. To dismantle the ion source, follow the procedure below. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 10-5 Maintenance Dismantling and Cleaning Procedures 1. Remove the ion source as previously described in the previous section. 2. Disconnect the source wiring leads from the feed-through. 3. Remove the filaments as described in an earlier section titled “Filament”. 4. The source assembly is built on four ceramic rods secured by a clamp. Caution!  The electron beam collimating magnets are fixed to the bracket at the top of the assembly nearest the connection ring. These magnets should NOT be removed.  Care must be taken to prevent contact between magnetic materials (e.g. a screwdriver) and the magnets.  These magnets have a high field strength but are very brittle and easily damaged if subject to impact. 5. Disconnect all leads from the source assembly, not the connection ring. 6. Remove the insulating rod clamp furthest from the connection ring. See Figure 10–5. Insulating rod clamp furthest from connection ring Figure 10–5. Removing the insulating rod 7. Take careful note of the sequence and orientation of the components. Detail changes to the exploded view below (Figure 10–6) may occur in special applications. 8. Remove the source component items in sequence. 10-6 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Maintenance Dismantling and Cleaning Procedures 9. Metal electrode surfaces can be cleaned with a fine abrasive such as diamond paste. Aim to remove discolourations and achieve a “shiny finish.” Ceramics can be cleaned with suitable detergent or acid. 10. Final clean as follows. If possible, use of an ultrasonic bath is recommended. a. Wash off all traces of abrasive pastes according to type. Use deionised water for water soluble pastes or recommended solvents as per manufacturer’s instructions. b. Final rinse with clean isopropyl alcohol or a similar solvent. c. Dry thoroughly, preferably in an oven at 100°C for one hour. 11. Reassemble the source assembly and refit to the analyser flange in reverse order. 12. Once reassembled, ensure that all plates are parallel. Check that the two focus half plates are aligned with each other. Figure 10–6. Source assembly Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 10-7 Maintenance Dismantling and Cleaning Procedures Magnet Pole Piece Assembly To clean the magnet pole pieces, proceed as follows. 1. Disconnect the wiring for the electromagnet coils from the magnet power and control PCAs, top RH side of the enclosure (Figure 10–7). Note the wiring sequence of the main coils to the power PCA. The electromagnet will fail to operate if these are not refitted in the correct sequence. Figure 10–7. Disconnecting the wiring 2. Using two 19 mm ratchet ring spanners, jack up the coils and yoke assembly until it clears the pole pieces (Figure 10–8). Ensure that the bolts are unscrewed evenly to avoid unnecessary strain to the threads. The bolts will now be free from the threaded hex pillars. Figure 10–8. Jacking up the coils and yoke assembly 3. Lift out the coil assembly (Figure 10–9). 10-8 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Maintenance Dismantling and Cleaning Procedures Caution! Heavy!  The electromagnet assembly weighs approximately 16 kg.  Protective footwear should be worn when performing this action. Figure 10–9. Lift out coil assembly 4. Unscrew the four pole piece locating screws and remove the front magnet pole piece (Figure 10–10). Locating screw Figure 10–10. Removing the front magnet pole piece 5. The Z-restrictor is a thin aperture plate positioned at the beam entrance to the electromagnet, left hand, source side, of the magnet assembly and held in place by the pole pieces. When the front pole piece is removed, slide out the Z-restrictor plate before removing the rear pole piece. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide 10-9 Maintenance Dismantling and Cleaning Procedures 6. Use diamond or other suitable abrasive paste to polish the surfaces of the magnet pole pieces and the Z-restrictor. Pay particular attention to the rectangular slot in the Z-restrictor. 7. Final clean as follows. If possible, use of an ultrasonic bath is recommended. a. Wash off all traces of abrasive pastes according to type. b. Use deionised water for water soluble pastes or recommended solvents as per manufacturer’s instructions. c. Final rinse with clean isopropyl alcohol or a similar solvent. d. Dry thoroughly, preferably in an oven at 100°C for one hour. 8. Visually inspect the magnet pole pieces for any remaining contamination, and repeat steps 6 and 7 if necessary. 9. Refit the rear magnet pole piece and Z-restrictor. 10. Refit the front magnet pole piece, taking care not to dislodge the Z-restrictor. 11. Lift the magnet / coil yoke assembly back into position. Engage the threaded bolts into the threaded hex pillars, and use the ratchet spanners to evenly jack down the assembly. 12. Reconnect the coil and search coil wires to the magnet power and control PCAs. Fuses Maintenance Hazard! Qualified Personnel Only! Before changing a fuse, isolate the instrument from the mains power supply and read the safety instructions provided in Chapter 2.  Fuses fitted are one of two body types. See Figure 10–11 and Figure 10–12. Figure 10–11. ATO (low voltage DC supplies only) 10-10 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Maintenance Dismantling and Cleaning Procedures Figure 10–12. 5 x 20 mm ceramic (mains supplies) Table 10–2. Power distribution unit fuses Fuse Number Supplied Unit Voltage Rating Type Manufacture F1 Magnet 30 V 10 A ATO Littelfuse 257 010 F2 Probe heater 24 V 2A ATO Littelfuse 257 002 F3 Auxiliary heater 24 V 2A ATO Littelfuse 257 002 F4 Inlet power 24 V 4A ATO Littelfuse 257 004 F5 Amplifier 24 V 1A ATO Littelfuse 257 001 F6 Turbo pump 24 V 4A ATO Littelfuse 257 004 F7 Vent valve 24 V 1A ATO Littelfuse 257 001 F8 Aircon fan 24 V 2A ATO Littelfuse 257 002 F9 CPU carrier 24 V 1A ATO Littelfuse 257 001 F10 User I/O 24 V 4A ATO Littelfuse 257 004 F11 Analyser 24 V 2A ATO Littelfuse 257 002 Table 10–3. CPU and user I/O carrier fuses Fuse Number Supplied Unit(s) Voltage Rating Type Manufacture F1 Digital O/Ps (non-voltfree) 24 V 2A ATO Littelfuse 257 002 F2 Digital I/Ps (non-voltfree) 24 V 2A ATO Littelfuse 257 002 F3 to F14 Digital O/Ps, Individual 24 V 1A ATO Littelfuse 257 001 Table 10–4. Inlet control fuses Thermo Fisher Scientific Fuse Number Supplied Unit(s) Voltage Rating Type F1 Mains heater 115/230 V 5A 5 x 20 mm FF F2 Solenoid valves 24 V 1A ATO Prima PRO & Sentinel PRO Mass Spectrometers User Guide 10-11 Maintenance Dismantling and Cleaning Procedures Fuse Number Supplied Unit(s) Voltage Rating Type F3 Inlet control and RMS drive 24 V 4A ATO Table 10–5. Ex isolation box (Ex systems only) 10-12 Fuse Number Supplied Unit Voltage Rating Type F1 PSU 115/230 V 1A 5 x 20 mm FF F2 PSU 115/230 V 1A 5 x 20 mm FF F3 Purge controller 24 V 500 mA 5 x 20 mm FF F4 Purge controller 24 V 500 mA 5 x 20 mm FF Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Appendix A Hazardous Area Operation Introduction A hazardous area is defined as an area where there is a risk of fire or explosion due to ignition of flammable gases, vapours, dusts, or fibres. Due to this risk, it is not possible to use standard electrical equipment in such an area without providing some form of additional protection to prevent ignition. This manual covers operation of the explosion protection features of the Prima PRO Ex and Sentinel PRO Ex systems. These instruments are essentially safe area systems. Explosion protection is achieved by pressurizing and purging the instrument enclosure to prevent ingress and build-up of flammable gas. The purge control equipment and any electrical apparatus outside the purged envelope (e.g. mechanical pumps) are protected by other methods as outlined below. Detailed operation of the purge control equipment used on a particular system is given in the respective manuals for that equipment, and these should be read in conjunction with this manual. Warning!  The specific points raised in this section should be carefully noted before carrying out any installation, commissioning, maintenance, troubleshooting, or upgrade work on an Ex system. This applies to ALL aspects of the work to be carried out, not just with regard to the hazardous area specific parts.  These points should be applied in addition to any national or local site regulations.  Failure to comply has the potential to cause a major site hazard. Caution! Thermo Fisher Scientific  There are other safety considerations related to working on Prima PRO and Sentinel PRO instrumentation regardless of the nature of the operating environment (safe or hazardous).  Specific safety issues are highlighted and covered in other chapters of this manual and should be taken into account in addition to any points raised below. Prima PRO & Sentinel PRO Mass Spectrometers User Guide A-1 Hazardous Area Operation Introduction Installation Before installing this equipment, verify that it complies with standards appropriate to the specific hazardous area.  Compressed air requirements: Supply pressure should be in the range 4 to 6.9 bar(g) (10 bar(g) if specified in order). Regulators are provided for each of the two compressed air functions. See Table A–6 for air flow requirements. The supply must be capable of maintaining the total required air flow at the above pressure. Failure to do so will result in power trips and / or alarms. The supply connection is 1/2” or 12 mm compression. Tubing of this diameter (minimum) should be used for a maximum run of 5 meters. Larger diameter tube / pipe should be used for longer runs. The exact requirements will depend on the supply pressure and line length.  Note the maximum allowable sample / exhaust pressure (see Table A–6).   Note the requirements of “Other Hazardous Area Considerations” later in this appendix. External enclosure materials are carbon steel (epoxy powder painted) and stainless steel. The enclosure should not be exposed to an environment that might cause significant degradation to any of these materials. Warning! A-2  Power and / or electrical data cables are NOT to be terminated in the purged instrument enclosure. All power and data cables must terminate in an external flameproof box (or boxes).  The main power supply, serial cables, and a limited amount of digital I/O connect to the flameproof box attached to the top of the main instrument enclosure.  Additional (wall mounted) flameproof boxes will be provided where I/O beyond that available in the base configuration is used.  Flameproof barrier glands (cable or conduit) must be used when making connections into flameproof boxes. Separate entries are provided for power and signal connections. Refer to Chapter 5: Installation & Interconnection for further details.  Data communication can be via fibre optic cables that are terminated direct within the instrument enclosure. When installing such cables through the user gland plate, suitable glands and cables must be used. See Chapter 3: Site Requirements and Chapter 5: Installation & Interconnection. Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Hazardous Area Operation Introduction General Hazardous Area Work Commissioning and Maintenance  Before starting work, check with the appropriate site authority. Permits to carry out live or hot work in the hazardous area may be required.  Work must be carried out by suitably trained personnel.  Before opening any electrical enclosures or using any electrical test equipment (test meter, laptop computer, etc.), ensure that the area has been verified as currently non hazardous. Continuous monitoring may be required.  Do not attempt to adjust any purge pressures, flow rates, or pressure set points unless appropriate test equipment is available. These have all been factory preset to give a safe operating condition.  Never use purge flow rates or timings other than those specified on the instrument label or in this document.  Do not attempt to modify the purge control equipment in any way. Doing so will void hazardous area certifications. If there is any evidence of modifications, the person on site with overall responsibility for hazardous area safety must be informed, preferably in writing. The factory should also be consulted.  Do not modify any part of the purged enclosure or the apparatus within the enclosure without first contacting the factory for written authorization because: a. There are other features of the system that are required for safe hazardous area operation over and above the enclosure purge. b. It cannot be assumed that any item of safe area electrical apparatus can be safely used in the purged enclosure. Thermo Fisher Scientific  Modifications could invalidate any hazardous area certifications and make the system unsafe.  When carrying out any work that involves breaking the analyser vacuum system, ensure that the area is verified safe for the entire duration that the vacuum system is open. This is necessary so as to avoid trapping hazardous gas inside the vacuum system that could be ignited on startup.  On completion of any work, ensure that where appropriate the system is returned to full purge protected condition (i.e. not in “override”). Ensure that covers are replaced on all electrical enclosures. Prima PRO & Sentinel PRO Mass Spectrometers User Guide A-3 Hazardous Area Operation Hazardous Area – General  When replacing any Thermo Scientific manufactured electrical assembly, ensure that the replacement assembly is of an issue level greater than or equal to the original.  When discussing spares, upgrades, etc. with the factory, make it clear that this is a hazardous area (Ex) system.  Verify correct operation of the purge control equipment on a six monthly basis (see “Purge Operation and Testing”).  Inspect and / or test the sample containment system on a six monthly basis (see “Inspection and Testing”).  Check correct operation of the RMS heater on a routine basis (see “Temperature”). Routine Checks Hazardous Area – General Area Classification This section gives a brief outline of the general principles of hazardous areas and operation of equipment in these areas, with comparison between European and North American terminology. Only hazards due to flammable gases and vapours will be considered. The presence of dusts and fibres may also cause an area to be defined as hazardous but will not be considered as the Prima PRO Ex and Sentinel PRO Ex are not approved for operation in such areas. Area classification specifies the probability of a hazard being present in a defined physical area. Under ATEX (Europe) and IECEx regulations, equipment is categorised based on the level of protection offered. Particular categories of equipment are allowed in particular areas. The areas and categories are summarized in Table A–1. Table A–1. Areas and equipment categories Hazard Type* Continuous or nearly continuous hazard ATEX (Europe) and IECEx Area Allowed Equipment Category Zone 0 1 North American Area Division 1 Intermittent hazard Zone 1 1 and 2 Hazard only in fault conditions Zone 2 1, 2 and 3 Division 2 *Refer to the appropriate standard for exact definition. A-4 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Hazardous Area Operation Hazardous Area – General Gas Classification Table A–2 categorises the gases that may be present in hazardous areas. Table A–2. Gas classification Typical Gas* Europe North America Propane / methane Group II A Class 1, Group D Ethylene Group II B Class 1, Group C Hydrogen Group II C Class 1, Group B Acetylene Group II C Class 1, Group A *Refer to the appropriate standard for a full listing of the gases in each group. Methods of Protection Most methods of protection rely on removing the source of ignition or separating it from the flammable gas. Hot surfaces represent a potential source of ignition and surface temperatures are classified as in Table A–3. Table A–3. Surface temperature classification Maximum Surface Temperature T Class 450°C T1 300°C T2 200°C T3 135°C T4 100°C T5 85°C T6 The T class for electrical apparatus represents the maximum surface temperature that can occur in normal operation or, if appropriate, a fault condition, and is normally determined as part of the certification process. A given hazardous area will have a specification for the T class for apparatus allowed to be used in that area. There are a number of methods of protection used to protect against ignition of flammable gases by sparks. Only those relevant to the Prima PRO Ex and Sentinel PRO Ex are considered here. Purge / Pressurisation Thermo Fisher Scientific This method allows a safe area electrical apparatus to be used in a hazardous area by placing that apparatus in an enclosure pressurised with clean air or an inert gas. The positive pressure in the enclosure ensures that any flammable gas external to the enclosure cannot enter the enclosure and be ignited by sparks, hot surfaces, etc. Depending on the area classification, it may be necessary to interlock the enclosure power to the enclosure pressure, i.e. if the pressure falls, the power will be switched off. Prima PRO & Sentinel PRO Mass Spectrometers User Guide A-5 Hazardous Area Operation Hazardous Area – General When purge protected apparatus is initially switched on, it is necessary to ensure that that there is no residual hazardous atmosphere in the purged enclosure. For this reason the enclosure is purged for a set time before the power is switched on. This time is the time (determined during apparatus certification) to purge the volume in the enclosure, including any partially trapped volumes. Again, depending on area classification, it may be necessary to automatically time this initial purge. Power is not allowed to be switched on until this phase is complete. Where the protected apparatus is an analyser, for example, it will be necessary to introduce sample gases into the enclosure. Typically, this gas is fully contained and would not enter the pressurised volume of the enclosure. If the sample gas is hazardous in nature then the possibility of leakage from this containment system into the enclosure must be considered. The simple enclosure pressurisation then becomes a continuous purge and the purge flow rate must be such that the worst-case internal leak is diluted to a safe level. A summary of the different purge types is given below. Table A–4. Purge types ATEX (Europe)/IECEx North America Area Purge Type Purge Characteristics Area Purge Type Purge Characteristics Zone 1, 2 Exp Automatic power interlock and purge timing Div. 1 Xpurge Automatic power interlock and purge timing Div. 2 Zpurge Manual power interlock and purge timing, pressurisation alarm The point at which purge gas exits the enclosure must be protected by a spark arrestor to prevent any sparks potentially generated by apparatus in the enclosure from getting into the hazardous area. Apparatus used to provide the required purge interlocking must remain powered even when the purge gas supply is off. Hence, the purge protection apparatus must use an alternative method of protection. Purge / pressurisation is the main method of protection used for the Prima PRO Ex and Sentinel PRO Ex systems, and detailed operation of these purge protection schemes is covered in later sections. Flameproof (Europe) or Explosion Proof (North America) A-6 This method does not attempt to prevent sparks or to isolate flammable gas from any potential source of ignition, and as such Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Hazardous Area Operation Hazardous Area – General ignition could in fact occur. The apparatus is, however, enclosed in a flameproof (or explosion proof) enclosure, which is rated to contain any combustion products such that: a. The enclosure remains intact. b. Hot gases cannot escape and propagate the combustion beyond the enclosure. Flameproof enclosures are hence very robust, typically of cast iron or cast aluminium construction. Flanges, etc. are designed so as to provide a long, well defined path length for hot gases to follow if they are to exit the enclosure. As a result, gases are sufficiently cool when they reach the outside (hazardous) environment so that further flame propagation does not occur. As a result of the nature of this protection, a particular flameproof enclosure is only certified for use with a particular set of gas groups (see above for gas group definitions). Flameproof enclosures may additionally be fitted with some form of weatherproofing seal, but this does not form part of the protection method. Cable entries to the enclosure must be of a type certified to maintain the flameproof integrity of the enclosure. This might involve some form of potting (with an epoxy compound) of the cable into a cable gland and may also restrict the type of cable that can be used (e.g. solid single core wires). On the Prima PRO Ex and Sentinel PRO Ex systems, flameproof protection is used for the electrical isolation enclosure(s) and the rotary pump motor. Increased Safety This is a “non-sparking” method of protection. It relies on methods of construction of the electrical apparatus that eliminate any possibility of sparking in normal operation. For example, screw terminals must be of a certified type that will not vibrate loose in service. The apparatus must be enclosed in a weatherproof enclosure (e.g. IP65) to prevent the ingress of conductive dusts or liquids that could cause sparks. This method is used for the purge controller / monitor unit. Non-Electrical Where possible, the use of non-electrical apparatus is an obvious way of avoiding electrical sparks. However, it should be noted this does not exclude the possibility of non-electrical sources of ignition such as mechanical sparks, hot surfaces due to friction heating, and static discharge. Commonly, this involves the use of pneumatics as an alternative and can be simpler than using protected electrical apparatus. Interconnection and servicing may also be simplified. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide A-7 Hazardous Area Operation Purge Operation In Europe, the ATEX directive encompasses non-electrical (as well as electrical) ignition sources and this must be considered when using pneumatic or other non-electrical apparatus in hazardous areas. Purge Operation Purge Overview The general principles of operation of a purge protected system have been outlined above. This section details how purge protection relates to the Prima PRO Ex and Sentinel PRO Ex systems. The enclosure is pressurised / purged with compressed air. For obvious reasons, the compressed air must be from a non-hazardous area source and free from contaminants such as oil and water. Typically, instrument grade air is used. Danger of Asphyxiation!  An inert gas such as nitrogen should not be used for the purge system.  There is no facility to duct away vented purge gas so the asphyxiation hazard is considerable if operated in a confined or poorly ventilated position. The standard instrument consists of a single enclosure, and purge air flows into the top of this main enclosure. A purge monitor unit located at the bottom left of the main enclosure allows the air to exit while also maintaining a back pressure in the enclosure. A continuous dilution and pressurisation (CDP) purge flow is required to dilute any internal sample leakage and maintain the internal enclosure pressure. The required flow has been determined (see below). As noted previously, an initial enclosure purge is required to remove any possible residual hazardous gas before power is switched on. The features of, and differences among, the three purge controller types used are outlined in the following table. A-8 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Hazardous Area Operation Purge Operation Table A–5. Types of purge controllers Exp X-purge Z-purge Power switch Electrical contactor interlocked to purge status and e-stop button Electrical contactor interlocked to purge status and e-stop button Electrical contactor interlocked to estop button Purge initialisation Automatic, following initial enclosure pressurisation Automatic, following initial enclosure pressurisation Manual Purge timer Electronic Electronic Manual Action on purge fail 4-second warning, then automatic power switch off 4-second warning, then automatic power switch off Alarm generated Purge fail override Controller function (password protected) Controller function (password protected) N/A Purge Operation Requirements The following tables specify the purge and air supply parameters required to ensure safe operation of the instrument. Thermo Fisher Scientific Prima / Sentinel PRO (non-Ex) + remote RMS (purged) Prima / Sentinel PRO Ex + remote RMS, and Sentinel PRO Ex + dual RMS Prima / Sentinel PRO Ex Table A–6. Parameter values and air requirements Enclosure Internal Free Volume 190 L 235 L 45 L Initial Purge Flow Rate 100 Nl/min 100 Nl/min 100 Nl/min Minimum Purge Time 11 minutes 15 minutes 3 minutes Minimum Quantity of Protective Gas Required 1100 L 1500 L 300 L Continuous Dilution and Pressurisation Flow Rate 100 NL/min 100 NL/min 100 NL/min Prima PRO & Sentinel PRO Mass Spectrometers User Guide A-9 Hazardous Area Operation Purge Operation Standard High Pressure Option* Minimum Supply Pressure 4 bar 4 bar Maximum Supply Pressure 6.9 bar 10 bar Maximum Enclosure Overpressure 15 mbar 25 mbar Regulator Set Pressure 3.0 bar 3.0 bar NOTE: The High Pressure Option must be specified in the instrument order. A Standard or High Pressure Option system can be operated at a higher line pressure, provided that an additional regulator and pressure relief device (set to 6.9 bar or 10 bar maximum respectively) are placed in the incoming air line. All purge parameters are detailed on the instrument label and must be adhered to. The parameters will have been set during factory testing. The CDP flow rate should be sufficient to pressurise the enclosure to a minimum of 1 mbar overpressure, but typically the operating pressure is greater than this – the set point of the enclosure pressure switch will have been adjusted to suit. Parameter Measurement In the event of any problems (or suspected problems) with the purge control equipment, or when certain part of that equipment is replaced, it may be necessary to set or check any of the above parameters. Before attempting this, suitable test equipment must be available. The requirements are as follows. a. Calibrated pressure gauge (0 to 20 mbar) for enclosure pressure measurement. If such a gauge is not available, a water manometer is acceptable (assume 10 mm of water column is 1.0 mbar). The pressure can be measured at any point on the main enclosure, but avoid points close to the air inlet. There may be a spare blanked port that can be adapted for this purpose. b. Calibrated flow meter for measurement of purge flow rates. Additionally, a pressure gauge should be used to measure the pressure at the flow meter inlet so the flow reading can be corrected for pressure. The pressure correction is given by: Flow = flow meter reading  (pressure reading (bar abs)) c. Stopwatch for verifying purge timing. A-10 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Hazardous Area Operation Purge Operation Sample Containment System Definition and Description The sample containment system is that part of the sample gas handling that runs inside the main enclosure and which therefore has the potential to leak into the enclosure. Once the sample passes into the vacuum system of the analyser, the pressure is sufficiently low that a leak into the purged enclosure cannot occur. For a Prima PRO Ex, the vacuum system can be considered as anywhere downstream of (and including) the inlet transfer line. For a Sentinel PRO Ex, it is anywhere after the membrane inlet. Any joint or seal in the sample containment system is considered as a potential source of internal release. It is necessary therefore to identify and quantify these potential sources and to do this, the maximum pressure within the sample containment system must be defined (see below). This is governed by pressure in both the sample and exhaust lines, and it is a user responsibility to maintain the value below the defined maxima for the instrument. Parameters  Maximum pressure in sample containment system (maximum pressure in sample inlets / exhaust) for Prima PRO Ex: 0.2 bar(g)*  Maximum pressure in sample containment system (maximum pressure in sample inlets / exhaust) for Sentinel PRO Ex: < 0.0 bar(g)†  Maximum leakage from sample containment system (Prima PRO Ex): 0.25 Nl/min Note: *It is a user responsibility to maintain this pressure and ensure it is not exceeded. †Pressure is maintained by use of a sample vacuum pump. See details below. Prima PRO Ex Leakage Handling Thermo Fisher Scientific The sample containment system is limited to a sample loop contained within the inlet stream selector, (RMS) valve, where physical joints have been kept to an absolute minimum. The worst leak occurs if the pressure transducer for the flow sensing fails mechanically or becomes disconnected. This is the maximum leakage (0.25 Nl/min) from sample containment system defined above. Prima PRO & Sentinel PRO Mass Spectrometers User Guide A-11 Hazardous Area Operation Purge Operation Combining this figure with the CDP flow rate shows that any such leak will be diluted to 0.25%, which satisfies the dilution ratio requirement. This is, however, the overall dilution ratio in the enclosure, and close to the leak point there is region where the leak must be considered as not fully diluted. As there are electrical items in close proximity to the point of release, it is necessary to treat these as potential sources of ignition, and additional precautions must be taken. A vacuum ejector pump, driven by a small fixed fraction of the purge air inlet, generates a suction flow that is connected to a port on the RMS sample tube bracket. This is arranged such that suction, the flow is > 5 l/min, is applied between the sample tube bracket and the pressure transducer PCB, and any leakage from the pressure transducer is drawn into the ejector airflow and diluted. The suction flow from the ejector is also used to assist in the initial purging of some internal volumes within the enclosure, specifically the turbo pump controller, the signal amplifier box, cold cathode gauge, and RMS stepper motor. Sentinel PRO Ex In the Sentinel PRO Ex, the situation is different in that flow through the sample loop (the sample containment system) is much higher compared to the Prima PRO Ex (typically 5 l/min), and there are connections within the loop that must be considered as potential leaks. It would require an unacceptably large flow of purge air to dilute any such leak to a safe level. The sample flow on a Sentinel PRO Ex system is induced by an external sample (suction) pump, connected to the common exhaust of the multi-stream inlet system (RMS). As a result, the sample loop is actually maintained under negative pressure and therefore, in normal operation, there can be no leakage out of the loop into the purged enclosure. In the event of a break in the sample loop, connection with the pump will be lost and sample will no longer be drawn down the sample line to the pump. It is necessary to consider that the sample line could be in a zone that is pressurised and could continue to drive sample down the line to the break in the sample loop (albeit at a much reduced flow rate). To provide protection, the sample loop is monitored by a pair (for redundancy) of vacuum switches that will detect either a break in the sample loop or a failure of the sample pump. Both result in a pressure rise. Note:  A-12 In the event of a loss of vacuum in the sample loop, the RMS drives immediately to the designated safe inlet, Port 1. Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Hazardous Area Operation Purge Operation  Port 1 must have a non hazardous and pressurised sample (e.g. instrument air) permanently connected so that the containment system is rapidly purged with this non hazardous gas. The operator is informed via an alarm that the action has taken place and normal sampling will have ceased. When the fault is corrected and vacuum re-established, normal sampling can resume. Due to the reduced pressure in the sample loop a connection from the vacuum ejector to the flow sensor bracket (as used on the Prima PRO Ex) is no longer necessary. However, this suction flow is still used to assist in the initial purging of internal volumes in the turbo pump controller, signal amplifier box, cold cathode gauge, and RMS stepper motor.  Inspection and Testing The purge system and sample containment system have been fully factory tested and should not require adjustment during the initial commissioning period. In order to maintain safe operation of the overall system, however, the integrity of the sample containment system should be checked periodically, at least annually, as part of a general preventative maintenance procedure. Leakage Dilution Test (Prima PRO Ex) The suction flow rate generated by the vacuum ejector should be checked. Disconnect the red tube (suction line) from the connector on the side of the RMS sample tube bracket. Check the suction flow rate at the free end of the tube using a suitable flow meter. The flow rate should be > 5 l/min. Vacuum Switch Test (Sentinel PRO Ex) The vacuum switch should be tested by disconnecting a line in the sample loop at the point where the loop exits the RMS (flowing towards the inlet probe assembly). Verify that the RMS switches to the safe inlet. Inspection The RMS rotary seals should be removed for inspection. It is recommended that spare seals are available in the event that the old ones are damaged before or during removal. Follow the instructions in “Appendix C: Technical Description: Inlet”. Note that the sample return seal is not important from a safety point of view – failure would only result in an inaccurate sample flow reading. Leak Testing Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide A-13 Hazardous Area Operation Purge Operation The above inspection procedure should always be carried out prior to leak testing. Testing will not, for example, detect a failure of one of the “back to back” sample tube seals. Warning!  This test involves pressurizing the RMS and appropriate precautions should be taken to avoid over pressurisation.  Correct fittings and blanks must be used.  Read this section in full and ensure that all the required parts are available before commencing. Remove the transfer line and blank the port with a 1/8” Swagelok plug. The RMS exhaust and all but one of the inlet ports must be blanked. If shutoff valves have been fitted in the sample lines these may be used if the pressure rating is appropriate. Otherwise, the individual ports must be blanked. Check that all the main RMS cover plate bolts are in place and tight. Connect a supply of a clean gas (e.g. nitrogen or helium) to the remaining RMS port via a suitable shutoff valve. Also, fit a pressure gauge (0 to 1 bar(g)) between this valve and the RMS (or use another blanked inlet port if this is easier). Pressurise the assembly to 0.5 bar(g). Close the isolation valve and disconnect the gas supply. Monitor the pressure. The test is passed if the pressure falls by no more than 0.05 bar in one hour. If a leak is suspected, search with a leak detector such as Snoop. Enclosure Leak Testing If it is suspected that leaks have developed in the enclosure, a search can be carried out during normal CPD operation. The enclosure pressure should be checked to verify that there is at least 2 mbar of over pressure; otherwise leaks will be difficult to locate. If required, the enclosure pressure can be increased by carefully restricting the purge vent from the system. Avoid pressures above 30 mbar as this can cause distortion of the enclosure and cause leaks that would not otherwise be present. Do not adjust the purge air inlet pressure or flow as a way of increasing enclosure pressure; this requires calibrated test equipment to allow it to be reset. External leaks can be located either by feel in the case of major leaks, or by using a bubble type leak detector such as Snoop. At the end of this test, remember to remove any purge outlet restriction. A-14 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Hazardous Area Operation Purge Operation Purge Operation and Testing All System Types This section provides further details on the operation and testing of the different purge types. The manufacturer’s operation and maintenance manuals for the purge controllers should also be consulted. If there are any doubts about any part of the following, consult the factory for further information. Power and signal switch box The flameproof enclosure mounted on top of the main enclosure contains the 24 Vdc power supply for the purge controller and the main power contactor. The contactor (and hence power to the instrument) can be switched off manually by the emergency stop switch on the side of the flameproof box (all purge types) or automatically (in the case of ATEX, IECEx and X-purge systems). It also contains the comms isolation PCB that provides relay isolation of the serial ports and a limited number of discrete digital signals in the event that the main power is shut off either manually or by the purge controller. Purge air inlet The unit contains a pressure regulator and needle valve to set the purge flow rate to the required level. Air flow into the enclosure is split to allow better distribution within the enclosure and flow is constant throughout the initial purge and CDP phases. ATEX, IECEx and X-Purge Systems The purge outlet / monitor unit is powered by 24 Vdc and handles all the purge control logic, timing, etc. and monitors the enclosure pressure and outlet flow rate. Pressure and flow set points are adjusted using controls within the unit that also provide the signal to operate the enclosure power control contactor (located in the power switch box, see above). The air exhaust incorporates a spark suppresser to ensure safe operation in the event of a serious internal enclosure problem. The purge controller includes an override function (password required) that enables the system to operate with the door to the purged enclosure open for maintenance purposes. A digital output from the purge controller provides an indication of the purge override status through the control interface software GasWorks and hence remotely via the available communication channels. To test the purge functionality, start with the system operating in full purge mode with the override off. Open an enclosure door – the instrument should be powered down at this point. Close the enclosure door to start the purge process. Use a stopwatch to check the initial purge time. Verify that at the end of the purge cycle the Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide A-15 Hazardous Area Operation Other Hazardous Area Considerations instrument power is restored. Switch the system into override and off again, and check that this is correctly indicated in GasWorks. Z-Purge Systems The purge outlet / monitor unit is powered by 24 Vdc and handles all the purge monitoring and logic. The enclosure pressure is measured and the pressure set point adjusted using controls within this unit. Spent purge air exits the enclosure through the unit that also maintains the system backpressure. A spark suppressor is incorporated in the exhaust to ensure safe operation in the event of a serious internal problem in the purged enclosure. A digital output is available from the purge controller and provides an indication of purge status through the control interface software GasWorks and hence remotely via the available communication channels. To test the purge functionality, open the enclosure door to simulate a purge failure and verify that the purge controller indicates this correctly. Check also that Z-Purge Status is indicated to be in the alarm condition in the system software. When the door is closed, the enclosure should pressurise, and after a few seconds the purge controller should indicate that the pressure is OK and the Z-Purge Status alarm will clear. Other Hazardous Area Considerations Temperature Over-Temperature Protection A-16 Hazardous atmospheres are prevented from entering the enclosure by means of the purge protection system. However, consideration also has to be given to the possibility that part of the system could be heated beyond the maximum temperature for the T class of the instrument. If this part is external, the hazardous atmosphere around the enclosure is then directly exposed to a hot, ignition capable surface. Similarly, if an internal component was to overheat, a potentially hazardous situation could arise if the enclosure door was opened before the component had cooled, even though power may have removed from the system. Most of the heated assemblies in the system are designed so that if full power is applied to the heaters a hazardous condition will not result. The exception to this is the main RMS body heater. Although this uses a controller to regulate temperature (up to 120°C), in a fault (runaway) condition certain regions could exceed the limits for the T class. Part of the heated body of the inlet is exposed to the external atmosphere and the thermal mass is such that internal parts would take a significant time to cool after power is switched off. To protect Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Hazardous Area Operation Other Hazardous Area Considerations the system from a controller failure a pair of independent thermal cutout switches (140°C) is fitted to the RMS body. The inlet temperature alarm (GasWorks software interface) should be monitored as this will give an indication that the thermal switches have tripped. Also, the temperature will oscillate in the 120°C to 140°C region. The enclosure temperature is monitored by the air conditioner, which generates an alarm when the temperature is outside the control window, and an independent temperature sensor, which triggers an alarm at 40°C. Batteries There are two batteries fitted within the instrument enclosure. Table A–7. Battery types within the instrument enclosure Processor Assembly Lithium thionyl chloride (Li/SOCl2) (Thermo Scientific supply) Type ½ AA Nominal capacity 1.2Ah Nominal voltage 3.6V Turbo Molecular Pump Lithium manganese dioxide (Li/MnO2) (3rd party supply) Type Coin cell Nominal capacity 48mAh Nominal voltage 3V Warning! Dry Gas Vent  Neither of these batteries is likely to need replacement during the lifetime of the instrument or pump respectively.  If a problem occurs, the complete assembly should be replaced.  No attempt should be made to replace the batteries.  See also the Battery Warning label on the inside of the instrument door. All Prima PRO and Sentinel PRO systems have a dry gas vent connection. Nitrogen (other inert dry gases could be used) is connected to the vent port on the vacuum system (via a regulator). When the vacuum system shuts down, it fills with the dry gas (rather than ambient air). This facilitates a much faster subsequent pump down. For hazardous area systems, the dry gas vent has an additional function. While the system is shut down it is possible for hazardous Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide A-17 Hazardous Area Operation Other Hazardous Area Considerations gas to enter the analyser vacuum system, either through the vent port if open to ambient air, or through the inlet system, if hazardous gases are still present. On restarting the pumps, it is feasible that the turbo molecular pump could cause ignition of the atmosphere with the analyser and that this combusting gas could propagate ignition to an external explosive atmosphere. Note:  Filling the analyser with nitrogen or other inert dry gas and maintaining a small positive pressure during any shutdown period prevents the possible ingress of flammable gases into the analyser.  Use of this inert gas vent is a requirement of the ATEX/IECEx certification of the system. Rotary Vacuum Pump General Thermal Trip Power for the pump (or pumps) is switched from within the main enclosure, although the pump is located externally and is independently protected for hazardous area operation. If the pump requires replacement, it should be noted that both the voltage and frequency of the pump need to be specified. Care must be taken to correctly reinstall the flameproof gland onto the replacement pump. The pump motor includes a thermal trip connected to the Ex Pump Thermal Trip on the instrument power distribution unit (PDU). In the event of an over-temperature condition, power to the pump will be tripped followed by a vacuum system shut down shortly after. This trip does not automatically reset; the Thermal Trip Reset button on the PDU must be pressed when the over-temperature condition has been removed. Note that the trip circuit contains a latching relay, such that the trip status is ‘remembered’ through instrument power cycles. For testing purposes, the functionality of the trip circuit can be checked by disconnecting the trip cable from the PDU and verifying that the pump switches off. The pump should not restart until the cable is reconnected and the reset button pressed. Purge A-18 Although the pump is certified for use in an external hazardous atmosphere, the internal flow path is not certified for pumping hazardous gas. For Zone 1 / Div. 1 applications, an inert gas Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Hazardous Area Operation Other Hazardous Area Considerations (typically nitrogen) purge is connected to the ballast port on the pump. The purge flow rate is selected so that in normal operation the oxygen content of gas passing through the pump is diluted to a level where ignition cannot occur. A flow of 0.6 l/min is required. A pair of flow switches is used to monitor the nitrogen flow (two switches are required to give redundancy). In the event of loss of flow, power to the pump is switched off, which will cause a full vacuum system shut down to take place shortly afterwards. Note that the pump purge shares the inert gas inlet connection with the dry gas vent. The flow interlock can be tested by turning off the nitrogen supply and checking that the pump switches off. The pump should restart when the nitrogen supply is restored. The flow switches have clear acrylic bodies to allow easy inspection of the devices. Check that the flow path is clean and the floats move up and down at more or less the same time when the nitrogen flow rate is adjusted. Calibration Panels The calibration panels are based on safe area solenoid valve manifolds. These are made acceptable for hazardous area use by mounting through the wall of the Exp enclosure, such that the valve bodies are outside the enclosure, which avoids possible leakage inside the enclosure. The solenoid coils are inside the enclosure and are therefore protected by the enclosure purge. Requirements of the assembly are that: a. The valve plunger assemblies, which contain gas and protrude into the enclosure, must be high integrity. The type of valve used has a welded plunger assembly, which is a requirement of the ATEX/IECEx certification of the system. Testing of the integrity of the plunger assembly is carried out in the factory where the welded assembly is tested as ‘infallible’. This is a requirement of ATEX/IECEx certification and has to be performed on each assembly prior to fitting to an instrument or making available as a spare. b. Substitute parts must not be used. c. The gasket seal between the valve manifold body and the mounting plate is designed to maintain the enclosure integrity and prevent calibration gas seeping into the enclosure in the event of a leak on the plunger-to-manifold O-ring. Care must be taken to correctly reassemble this gasket. It is recommended that this gasket is replaced should it prove necessary to strip down the assembly for maintenance purposes. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide A-19 Hazardous Area Operation Other Hazardous Area Considerations Air Conditioner The air conditioner is made suitable for hazardous area operation by locating ignition capable parts of the system within the purged enclosure. The only parts exposed to hazardous atmospheres are the condenser coil and the air circulation associated with this. Air circulation over the condenser coil is achieved by use of air amplifiers as fans, suitable for all area classifications were considered inappropriate, principally due to size. Air amplifiers are non-electrical and have no moving parts. Three air amplifiers are used in parallel to ensure good air distribution over the condenser coil. The compressed air requirement is 100 to 300 Nl/min, dependent on ambient temperature conditions, and controlled by the onboard regulator. Remote / Dual RMS RMS and Instrument in Hazardous Area The remote RMS (or second RMS in a dual valve configuration) is housed in its own enclosure. This additional enclosure also requires pressurising and purging to enable it to be used in a hazardous area. There are two variants. The remote RMS enclosure is linked to the main enclosure via a 32 mm conduit that carries all the required connecting cables and pipe work, and an additional 16 mm conduit, which is deliberately empty. Two conduits are required to ensure there is an unobstructed path for purge air to flow from the remote to main enclosure (obstruction of this path could result in an overpressure condition in the remote enclosure). Serial purging of the enclosures is used where compressed air is connected to the remote RMS enclosure via a regulator and is ducted to the main enclosure through the interconnecting conduit. Compressed air will also be required at the instrument enclosure, to operate the air conditioner air amplifiers, so there are two compressed air connection points to instruments with this configuration. Compressed purge air will then exit the main enclosure through the purge controller as normal. As the air flows into the remote RMS enclosure first this will be at a higher pressure than the main enclosure. Providing the pressure and flow rate detected by the purge controller in the main enclosure are within required limits, then the purge status of the remote RMS enclosure must also be OK. RMS in Hazardous Area and Instrument in Safe Area A-20 In the case that RMS is in a hazardous area and the instrument in a safe area, the remote RMS is a self-contained purged unit with purge controller and compressed air regulator mounted on the side. Rather than use an Exd enclosure for power isolation, the appropriate components are located in the main instrument enclosure, communicating with the purge controller via a cable in the 32 mm Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Hazardous Area Operation Service Replacement Items conduit. To maintain the purge integrity of the RMS enclosure, the conduit is internally sealed. Due to the complexity of isolating all the signal and power lines to the RMS enclosure, in the event of loss of purge (ATEX, IECEx and X-Purge systems) power to the whole instrument is switched off. The purge requirements for these two cases are different and are also different to the standard (local RMS) case. Details of the purge parameters are given earlier in “Purge Operation Requirements”. The previous section (“RMS and Instrument in Hazardous Area”) is also valid for the purge arrangement of a dual RMS Sentinel PRO Ex. A dual RMS Prima PRO Ex is not an allowable configuration due to the difficulty of handling the gas line from the second, remote RMS within the purged enclosure. Sample Pump (Sentinel PRO Applications) Fibre Optic Communications The pump in Sentinel PRO applications is powered independently of the instrument and will, in general, require 3-phase power. The pump will need to be hazardous area protected in its own right. Note that the pump might be exposed to explosive gases via both the external atmosphere and the internal flow path. The requirements in the case of the latter will vary depending on the local regulations in force and the area classification. Note that systems using fibre optic require a different ATEX/IECEx certification code compared to the standard systems (see Figure A–2 through Figure A–9). Adding fibre optics might therefore require a change to the instrument label. Only fibre optic converters supplied from the factory should be used. Information on the type of fibre optic cable allowed and how to connect is given in Chapter 3: Site Requirements and Chapter 5: Installation & Interconnection. Service Replacement Items In order to maintain the system safe for hazardous area use and to maintain its certification, it is essential to replace any faulty item with an identical model, part, etc. Similar versions might possess subtle differences that could adversely affect safe operation. If in doubt, consult the factory. A number of items, such as turbo molecular pump electronics, Penning gauge, RMS stepper motor, and signal amplifier have been adapted to ensure internal volumes are purged by means of suction from a vacuum ejector (see “Leakage Handling”). In the case of third party supplied components, these have not been physically modified but have had fixing screws, or similar, replaced with a special hollow adapters to allow for connection to the ejector circuit. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide A-21 Hazardous Area Operation Service Replacement Items Caution!  In the event that one of these third party items has to be replaced, the purge adapter screw(s) must be removed and retained.  Refit the adapter(s) to the replacement item before refitting.  Reconnect the ejector lines before putting back into service. The original screws are stored within the enclosure. These can be fitted to the faulty item if it is being returned for servicing, investigation, etc. In the event that any cable gland in the enclosure need replacement, it is important that the correct size and type of gland are used. See Figure A–1 for identification of these glands. Size: M32 Type: Exd into isolation box. IP40 into enclosure Size: M20 Type: Exe Size: M20 ext, 1/4” BSP int Type: Nickel plated brass, pipe bulkhead Rotary pump cable (rear corner) Size: M20 Type: Exd Size: M32 Type: Exe 2nd rotary pump (where used) Size: M20 Type: Exe blank (no pump) or Exd (pump fitted) Size: M16 Type: Exe with internal seal around cable Size: M16 Type: Exe Size: M20 Type: Exe Glands specified as Exe must be either Exe certified or metal, minimum IP40. Figure A–1. Enclosure cable glands A-22 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Hazardous Area Operation Troubleshooting Troubleshooting This section provides a brief guide to identifying the cause of some common problems that may be encountered. It should be noted that the majority of problems are due to air supply faults or enclosure leakage and that problems with purge control equipment are rare. Ensure that “Safety Information” (Chapter 2) has been read and observed before starting any work. Check that the correct test equipment is available before making any adjustments that cannot be reversed. Manufacturer’s documentation should be consulted in parallel with this document. Table A–8. Troubleshooting Symptom* Possible Cause Action 1. Purge sequence fails to start, enclosure power off, purge timer does not run. a. Air supply pressure low or line capacity inadequate. Check pressure at instrument. Increase line capacity (bigger diameter line, shorter line length, or different air source). b. Enclosure leaky. Cannot be sufficiently pressurised. Check enclosure pressure. Check recently removed panels, and inspect door seals. Carry out enclosure leak check procedure. c. Air inlet filter blocked. Filter may block after extended operation period or due to oil or debris in the air supply. Remove and clean. Note: A contaminated air supply can cause problems to the instrument in the main enclosure. Rectify fault and clean lines before restarting. d. Power off to purge controller. Check power supply to controller Note: Fuses in main power switch box. e. Pressure sense faulty or set point incorrectly adjusted. Check for contamination around vent (internal sense port could be blocked). Check enclosure pressure, set point function, and adjustment. f. Other controller fault. Thermo Fisher Scientific Refer to manufacturer’s documentation or consult factory. Prima PRO & Sentinel PRO Mass Spectrometers User Guide A-23 Hazardous Area Operation Troubleshooting Symptom* Possible Cause Action 2. Purge timer starts but resets, or enclosure power not switched on at end of purge. a. Purge flow depletes supply and causes pressure drop. Check pressure at instrument. Increase line capacity (bigger diameter line, shorter line length, or different air source). 3. Initial purge generally correct, but controller occasionally trips out enclosure power / alarm. a. Intermittent air supply fault. Check for other equipment using the same air supply, which may cause pressure drops. Monitor air supply pressure. Check air supply capacity is not marginal. Modify air supply as required. b. Enclosure pressure too close to set point. Treat as possible causes (b), (c), and (e) listed for symptom 1. Adjust pressure set point only after carrying out other checks. Purge actual time not as set. c. Intermittent controller fault. Treat as possible cause (e) for symptom 1 and possible cause (a) for symptom 2. Timer faulty. Contact factory. *Note: The description of the symptom applies to European and X-Purge systems. In the case of Z-Purge systems, some of the points are not applicable, and the following points should be noted. A-24  The enclosure power trip is replaced by a purge fail alarm.  There is no automatic initial purge. The indicators should be observed to find out if the enclosure pressurisation has been sensed or the safe purge detected. Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Hazardous Area Operation Standards Conformance Standards Conformance The Prima PRO Ex and Sentinel PRO Ex instruments are approved to ATEX (Europe) and IECEx standards (depending on the model of purge controller, flameproof switchbox and external rotary pump fitted) as shown below: ATEX EN 60079-0:2012 + A11:2013 EN60079-2:2014 IEC IEC 60079-0:2011 6th Ed, IEC 60079-2:2014 6th Ed IEC 60079-28:2015 2nd Ed Figure A–2 to Figure A–9 show the instrument labels and give the full certification details for the Prima PRO Ex and Sentinel PRO Ex respectively. Refer to the completed labels fitted to a specific instrument to determine whether it is ATEX and/or IECEx approved. For applications in areas using North American standards, the Prima PRO Ex and Sentinel PRO Ex are designed to comply with NFPA 496. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide A-25 Hazardous Area Operation Standards Conformance Figure A–2. Prima PRO Ex instrument label A-26 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Hazardous Area Operation Standards Conformance Figure A–3. Prima PRO Ex with fibre optics instrument label Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide A-27 Hazardous Area Operation Standards Conformance Figure A–4. RMS enclosure label (Prima PRO Ex with remote RMS) Figure A–5. RMS enclosure label (Prima PRO Ex with remote RMS and fibre optics) A-28 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Hazardous Area Operation Standards Conformance Figure A–6. Sentinel PRO Ex instrument label Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide A-29 Hazardous Area Operation Standards Conformance Figure A–7. Sentinel PRO Ex with fibre optics instrument label A-30 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Hazardous Area Operation Standards Conformance Figure A–8. RMS enclosure label (Sentinel PRO Ex with remote RMS) Figure A–9. RMS enclosure label (Sentinel PRO Ex with remote RMS and fibre optics) Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide A-31 Appendix B Technical Description: System Introduction to the Prima PRO Hardware Main Components The Prima PRO instrument is an industrial process analyser based on a scanning magnetic-sector mass spectrometer with a 6 cm radius. The variable magnetic field is produced by an electromagnet with a laminated core that enables rapid and extremely stable analysis of multiple user defined gases. The instrument is designed for continuous operation in a process environment and is configured for ease of maintenance and simplicity of operation. With the exception of the host PC, all components are mounted either within or on the instrument enclosure and are modular for ease of replacement. The main components are provided in the following table. Table B–1. Prima PRO hardware - Main components Component Description Data system Control of all the Prima PRO functions is via an integral embedded processor in the instrument enclosure. This processor also handles communication with the host PC, DCS, etc. Thermo Fisher Scientific Electronics Provides the required power supplies, etc. for the mass spectrometer. Analyser Comprises ion source housing, magnet assembly, and detector housing (collector area). Rotary pump Provide backing pressure for evacuating the analyser and also provides inlet pumping. High vacuum pump Turbo molecular pump and controller. Prima PRO & Sentinel PRO Mass Spectrometers User Guide B-1 Technical Description: System Principle of Operation Magnet control RMS valve Electromagnet Inlet probe Vacuum gauge Amplifier & detectors Inlet controller A/C unit Source assembly AC power distribution Vacuum housing DC power distribution Turbo molecular pump Analyser supplies Embedded controller Digital & serial I/O Figure B–1. Hardware components Principle of Operation Sample gas is ionised by electron impact in the source. Ions injected into a magnetic field will describe a circular orbit where the radius is dependent on the initial velocity of the ion, its mass, charge and the strength of the magnetic field. This relationship is described in Equation 1: R2  MVx H2 z constant Equation 1. Where: R = radius of orbit M = mass of the particle V = voltage applied to the particle to accelerate it to velocity ‘v’ H = magnetic field z = charge on the ion B-2 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Technical Description: System Principle of Operation For a fixed radius, the equation reduces to Equation 2: constant  MV H2 Equation 2. Figure B–2. Separation of ions through the magnetic sector For an electromagnet with a fixed accelerating voltage the equation can be reduced to Equation 3: M  H2 Equation 3. This is the basic mass spectrometer equation used by Prima PRO instrument. If a fixed position ion detector is placed at the exit from the electromagnet, the mass of the ion arriving at the detector can be selected by varying the magnetic field. Refer to Figure B–2. The ion signal measured at the detector is then proportional to the concentration of the corresponding component in the sample gas. This enables the mass spectrometer to be used as a compositional gas analyser. The constant of proportionality is determined by calibration against known gas standards. Analysis and calibration may be complicated by overlapping mass spectra as a result of the sample gas mixture. Methods to make such overlaps less convoluted are discussed later. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide B-3 Technical Description: System Vacuum System Vacuum System The Prima PRO vacuum system consists of the listed in the following table. Table B–2. Prima PRO vacuum system components Component Description Analyser assembly The chamber that contains the ion source, the magnetic sector flight-tube, and collector assembly. Turbo molecular pump A mechanical pump capable of producing and sustaining ultra high vacuum (hydrocarbon-free) in a relatively short period. The pump is mounted vertically below the main analyser vacuum housing. All turbo molecular pumps must be used in conjunction with a mechanical rotary pump that maintains the backing pressure in the molecular flow regime required for the turbo molecular pump to operate. Rotary pump An 8m h two-stage rotary pump is fitted below the analyser enclosure. The turbo molecular pump and inlet bypass are backed by both stages of the rotary pump. The Sentinel PRO does not have an inlet bypass arrangement. Penning gauge A glow discharge device that operates within the pressure range -5 -7 5 x 10 mbar to 1 x 10 mbar and monitors the pressure in the analyser vacuum chamber. The gauge is controlled by the ASU and the output relayed to the control PC for display on the user interface status page. The primary function is to interlock the ion source filament and analyser high voltages supplies in the event of accidental vacuum loss or high pressure. Air admit valve To prevent migration and loss of bearing lubricant, the turbo molecular pump should always be held at atmospheric pressure when switched off. To ensure this happens, the pump is fitted with a valve that automatically vents to atmosphere when the pump is switched off or power is lost to the system. The vent line is protected by a filter which protects the valve from contamination and throttles venting rate. The vent line opens into the compression stages of the turbo molecular pump so that the gas is distributed evenly to the high vacuum and backing pressure vacuum sides. 3 -1 A dry gas vent connection, 1/4” / 6 mm Swagelok fitting, is provided on the left hand side of the enclosure above the isolation switch (safe area instruments) or purge control unit (hazardous area instruments). B-4 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Technical Description: System Ion Source Component Description Foreline trap Sentinel PRO systems include a foreline trap fitted immediately above the mechanical rotary pump to prevent oil vapour back-streaming due to low backing line pressures. On Prima PRO systems this is not required due to the viscous flow of sample gas into the rotary pump, from the inlet bypass line, which suppresses vapour back-streaming. Ion Source Atoms or molecules of gas must carry an electrical charge before they can be analysed, i.e. they must be ionised. Ionisation takes place in the ion source where a beam of electrons is passed through the sample gas. Electrons that either collide with or pass in close proximity to the sample gas molecules cause electrons to become detached from or adhere to the molecule. In the former case, the ion formed will be positively charged; in the latter, negatively charged. Positive ions are used exclusively for the analysis. The electron beam is derived from a hot wire filament and is focused magnetically through the ion source. The effect of the magnetic field on the electron beam is similar to that experienced by ions in the magnetic sector and they will describe a circular path. Due to the smaller mass of the electron, however, the paths have a much smaller radius and the beam tends to spiral along the lines of magnetic field. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide B-5 Technical Description: System Ion Source Source magnets Filament assembly Electron beam Sample inlet Figure B–3. Ion source Figure B–3 illustrates the ion source. The electrons are drawn to the source by a positive potential and then pass through the source via apertures on either side. They are collected on an electrode, referred to as the electron trap, on the opposite side of the source. The ribbon of electrons interacts with some of the molecules of the sample stream and forms a cloud of ions in the source cavity. A single exit slit from the source is positioned close to the path of the electron beam, and therefore the ionisation region. By creating a negative potential difference between the source block and an additional electrode, the source slit, positive ions are drawn out of the ion source. The ion source is held at a potential above ground termed the ion energy: for the Prima PRO this is 1 kV. Ions leaving the source through the exit slit pass between two half plates which focus and steer the beam. The potential difference between the two plates is varied to steer the beam on to the source slit. The voltage difference between the mean half plate voltage and the ion source block is varied to focus the ion beam. The ion beam leaves the source assembly via the alpha slit, which trims the beam height prior to injection into the sector. Inside the ion source an additional electrode, referred to as the repeller, is positioned directly opposite the ion exit slit. Operating at B-6 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Technical Description: System Ion Source a positive potential relative to the ion source helps move positive ions out of the source and improves the ion extraction efficiency. The number of ions formed depends upon both the quantity of molecules in the ion source and the electron current. The electron current is monitored on the trap electrode and a feedback circuit in the analyser supplies unit (ASU) adjusts the filament current so that electron flux is maintained at a constant level. The electron beam and ion exit apertures are the only openings in the ion source which is otherwise fully enclosed. Introduction of a sample gas to this enclosure results in a higher pressure environment inside the source enclosure compared with that of the surrounding vacuum chamber where the filament assemblies are positioned and operate. This pressure differential helps suppress instrument backgrounds, inherent in the vacuum chamber, and reduce effects due to sample / (hot) filament interactions. Figure B–4 illustrates the arrangement of the Prima PRO ion source assembly. This is of the Nier type, in which ionisation is achieved by collision of the sample molecules with a collimated electron beam; the source materials are primarily ceramic (alumina) and stainless steel. All the source components are aligned by four precisionground ceramic rods fixed to the source mounting flange and the assembly is held in place by the source clamp. Source mounting flange Source block Source slit Z-Restrictor Ion exit plate Source clamp Half plates Alpha slit Figure B–4. Prima PRO ion source assembly Filaments Selection of a filament There are two commonly used filament materials on the Prima PRO (others may occasionally be used for special applications). Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide B-7 Technical Description: System Ion Source Thoriated Iridium The emissive material is a thoria (thorium oxide) coating on an iridium wire support. This has a lower work function than other common filament materials such as tungsten and rhenium. Thoriated iridium filaments are recommended for operation at low pressures and low pumping speeds since less out gassing occurs due to the lower working temperature of the filament. This also makes the filament more tolerant of operation under conditions of overpressure and is less likely to “burn out” and fail. Thoriated iridium filaments are used for the majority of applications on the Prima PRO and Sentinel PRO. Tungsten Thoria Alloy This material is a 1% ThO / 99% W alloy and is formed into a coiled wire, which gives prolonged life for hydrocarbon applications, particularly where there is greater than 20% of hydrocarbon compounds of molecular weight higher than 40. Filament Current Limit The filament current limits for each of these materials are given in the table below. Table B–3. Filament current limits Filament Current Limit (Amps) Thoriated iridium 3.1 Tungsten / ThO alloy 3.0 Figure B–5 shows how the filament is mounted to the source block. Figure B–5. Mounting of the filament onto source block B-8 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Technical Description: System Mass Analyser Mass Analyser Refer to Figure B–6. For a given magnetic field (i.e. a given magnet current), only ions of a specific mass to charge ratio will reach the mass spectrometers collector. Masses that are lighter than that for which the instrument has been tuned will be deflected more and masses that are heavier deflected less. Therefore, the higher the mass of ions to be detected the higher the magnetic field and consequently the higher the magnet current. H  Im Equation 5. Where: Im = magnet current H = field created by the electromagnet Figure B–6. Separation of ions through the magnetic sector Collector Two detectors are available in the collector assembly (the Faraday detector and the optional MCP, the operation of which are described below. In conventional sector mass spectrometers, compensation for errors in analyser geometry, magnet fringing field effects and beam aberrations, resulting from localized, contamination induced charge effects is achieved by adjusting the magnet position. In the Prima PRO instrument, this is addressed by fixing the position of the magnet and using a quad lens positioned before the collector to compensate for and adjust the position of the refocused beam image. This lens is capable of producing either a converging or diverging beam profile as required to adjust the effective focal length of the instrument and thereby trim minor changes electronically. The Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide B-9 Technical Description: System Ion Detection voltages applied to the two pairs of quadrupole rods are equal and opposite. The quad lens DAC voltage can be varied from -25 V to +25 V but, in practice, a variation of a few volts positive or negative is usually sufficient to achieve a symmetrical, flat-topped, peak that provides good, long-term precision from the analyser. The deflector lens is used to divert the ion beam through one of two resolving slits. The size of the slit is generally chosen so the instrument can resolve adjacent peaks at the high mass end of the scale. The higher the mass, the wider the peaks become. A disadvantage of using a single slot is that low mass peaks are, in comparison, very narrow making these peaks more susceptible to drift in mass scale. On the Prima PRO instrument, two resolving slits are fitted – one for low mass peaks (e.g. typically below mass 20 for the Prima PRO and below mass 100 for the Sentinel PRO) and one for high mass peaks. The normal resolving powers used are 20 and 60 for the Prima PRO and 85 and 140 for the Sentinel PRO. The Faraday / multiplier deflectors divert the ion beam onto either the Faraday or optional MCP detector. With a positive voltage applied to the Faraday deflector (F-def) and the multiplier deflector (M-def) grounded, the beam is diverted into the Faraday detector. When a positive voltage is applied to (M-def) and (F-def) is grounded, the beam diverts on to the MCP detector. The resolving stack and detector assemblies are illustrated in Figure B–7. Quad lens MCP assembly Deflector electrodes Detector connections Faraday assembly Figure B–7. Resolving stack and detector assemblies Ion Detection MCP Detector Assembly B-10 The output of the MCP detector assembly is an electron current with a magnitude 103 or 104 times that of the ion current striking the plate Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Technical Description: System Ion Detection and depends on the voltage applied. Operation of the MCP is described below. Electron current exiting the MCP is picked up on the detector electrode which connects directly to the amplifier mounted on the front right face of the vacuum housing. Figure B–9 illustrates an MCP that consists of an array of millions of glass capillaries, each of which acts as secondary electron multipliers to form a large secondary electron multiplier array. Each channel has an internal diameter of 25 µm and are fused together to form a thin disk 0.8 mm thick. The inside wall of each channel is coated with an electron emissive material the ends of each channel is covered with a thin metal film to form an electrode. Each channel is therefore an independent secondary electron multiplier. When a voltage is applied across the ends of the capillaries, an electric field is generated along the axis of each channel. When an ion strikes the entrance wall of the channel, secondary electrons are produced. The secondary electrons are accelerated by the electric field and travel along the parabolic trajectories determined by their initial velocity. When these electrons strike the opposite wall of the channel, additional secondary electrons are produced. This process is repeated many times along the channel and as a result, the electron current increases exponentially towards the output of the channel. The capillary bundles are sliced into thin disks with a slice angle chosen to ensure that primary electrons cannot pass through the channel without subsequently colliding with the channel wall. MCP Operation The MCP should not normally be operated at voltages exceeding 1200 V. Optimum results are normally obtained at a gain setting of 1000. At this value detector noise is negligible and the life of the MCP assembly is prolonged. Caution! Damage to the MCP! Ion currents in excess of 1 x 10-12 A should never be applied to the MCP as irreversible damage, requiring replacement of the MCP, will occur. For normal analysis the MCP should only be used for peaks less than 100 ppm.  Calibration of the MCP requires that the voltage needed to produce a certain gain is established. This is achieved by measuring the ratio of peak intensity on the Faraday and MCP array as follows. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide B-11 Technical Description: System Ion Detection 1. From the Instrument Control Panel, select the Detectors tab and Multiplier Calibration from the drop down function box (Figure B–8). Figure B–8. Multiplier Calibration 2. Choose a suitable mass with a peak height in the range of 1 to 8 x 10-13 amps on the Faraday detector. Start the scan (by clicking on the Start Scan button) and observe the multiplier gain as a function of the multiplier voltage. 3. Click on the Add Cursor button and set the cursor to the required gain. 4. Click on the Set DAC button to set the voltage to give the required gain. Figure B–9. Micro channel plate B-12 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Technical Description: System Introduction of a Gas Sample Faraday Detector Introduction of a Gas Sample Ions collected in the Faraday bucket result in a current that is sensed and then amplified to a suitable level in the instrument amplifier. The Faraday bucket is light tight and coated with colloidal graphite to reduce emission of secondary electrons that would otherwise cause a false indication of ion current. Further suppression is provided at the entrance to the detector by a suppressor plate, biased at approximately -40 volts and magnets that create a field around the bucket to ensure any electrons emitted remain confined. Gas samples are introduced into the ion source through the inlet probe assembly. For a Prima PRO, gas is sampled through a micro capillary in the stream selector assembly (RMS, solenoid, or single point), passes along a transfer line, into the inlet probe, and finally down a bypass line to the rotary vacuum pump. In the inlet probe, a small portion of the gas flowing through the assembly passes through a further leak element into the ion source. The flow of gas through the capillary and inlet probe is viscous in nature. It is desirable that the flow through the leak element should be molecular, i.e. of the same characteristics as the flow out of the ion source. Failure to achieve this can result in a distortion to the composition of the gas as presented to the source, specifically a depletion of light gases with respect to heavier gases. The leak elements used are typically a pinhole type (commonly 70 µm diameter, but other diameters may be used depending on application). For leaks of this diameter, flow is predominately molecular if the pressure of gas at the leak is around 1 mbar. The length and diameter of the bypass line are chosen such that this pressure is achieved. The leak element therefore forms the transition point between viscous and molecular flow. The flow through the capillary is 7 to 10 ml/min, while the flow rate through the leak element is around 5  10-4 mbar l/s, i.e. only a small fraction (<1%) of the gas entering the system through the capillary passes to the ion source, the bulk of the sample passes to exhaust through the rotary pump. The flow path through the capillary, transfer line, inlet probe, and bypass line to the pump can be considered as a fast loop, so that changes in sample gas composition are rapidly transmitted to the inlet probe. A typical arrangement (in the case of an RMS inlet system) is shown in the following figure. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide B-13 Technical Description: System Introduction of a Gas Sample To bypass line and vacuum pump Transfer line Figure B–10. Typical arrangement of RMS inlet system The Sentinel PRO introduces the gas sample directly from atmospheric pressure via a membrane inlet. The dimethylsilicone membrane is fitted to the end of an inlet probe, which replaces the leak element in the Prima PRO assembly. The end of this stainless steel inlet probe locates onto the ion source and is insulated by a ceramic end piece. The selected sample gas flows from the stream selector, RMS, to the inlet probe and membrane, and then returns to the stream selector to be exhausted. This loop operates at a reduced pressure, typically approximately 0.8 bar(a), generated by a large capacity circulator pump attached to the RMS valve to draw sample to the instrument. The membrane inlet is used as this provides preferential transmission of organic compounds compared with the principle air constituents. The concentration of organic compounds entering the ion source is increased by a factor of between 10 and 100, which gives significantly improved detection limits for these components, compared with a standard capillary inlet. B-14 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Technical Description: System Mass Spectrometer Parameters Mass Spectrometer Parameters Sensitivity Whenever the instrument completes a calibration, a calibration report is produced that details the sensitivity and relative sensitivity of each analyte. The sensitivity indicates the ion current as measured at the collector and is proportional to the percentage of a particular analyte in the gas used for calibration. Equal pressures of different gases in the ion source do not necessarily produce an equal ion current. This is due partly to differences in molecular ionisation cross-sectional area, those with a larger area being more easily ionized, and in part due to the different transmission efficiency of the analyser for ions of different mass. Consequently a sensitivity factor, relative to a reference analyte, is calculated. This factor is known as the relative sensitivity. For the calibration report, relative sensitivity is calculated as being the sensitivity of the analyte relative to the base gas defined in the gas database. For example, if the relative sensitivity of nitrogen measured by the instrument is 1.0 and helium measured by the instrument is 0.2, for equal quantities of nitrogen and helium in the ion source the ion current measured for nitrogen will be five times that of helium. Resolution The resolving power or resolution indicates the highest adjacent mass numbers that a particular instrument can separate. The definition used is known as the 10% Valley definition. This states that the resolving power of a mass spectrometer is the highest mass number at which peaks of adjacent molecular weight and equal heights have a valley between them of 10% of the peak height. Figure B–11 shows the appearance of two such mass peaks. The intensity of the two peaks is additive, and if each contribute 5% at the midpoint between them, then the net effect is a 10% valley. For example: If an instrument has a resolving power of 100 by this definition then, if peaks of equal height could be formed at mass 100 and mass 101, the valley between them would be 10% of the height of either peak. At lower masses, the valley between adjacent masses is reduced, and at higher mass numbers, the valley between adjacent masses increases. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide B-15 Technical Description: System Mass Spectrometer Parameters Figure B–11. Two mass peaks of adjacent molecular weight and equal heights A 5% Peak Height definition is exactly the same as the 10% Valley definition and is illustrated in Figure B–12. This is an easier definition to apply in practice since the peak width at 5% level of the peak height can be easily measured. For example, in air when examining the nitrogen 28 peak, the peak width at the 5% height can be measured and related to the difference between mass 28 and mass 29. If the 5% width proved to be equal to 0.7 of the distance between mass 28 and mass 29 (assuming the peak is centred exactly on 28), then the resolving power is given by 28/0.7 = 40. This indicates that the 10% Valley definition would apply to peaks of equal height at masses 40 and 41. Figure B–12. Comparison of 5% Peak Height definition and 10% Valley definition B-16 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Technical Description: System Cracking Patterns Cracking Patterns The sequence of peaks representing a particular gas species is a direct result of how that species reacts under electron impact in the source. Depending on the species, the molecules can undergo a variety of reactions within the ion source, and the resultant set of peaks is referred to as the “cracking pattern.” A single gas species may produce a variety of different ions giving rise to several peaks of different mass-to-charge ratio and intensity. The relative intensities of these various peaks are characteristic of the gas species in question, although the peak intensities may be affected by changes in source conditions (such as electron energy). The relative intensities of the different peaks can be used to de-convolute the composition of a gas stream containing components of the same molecular weight. Ion Types Some of the different types of ions that can be produced within the ion source are described below. Molecular Ion This is the simplest reaction to understand and results from the gas molecule acquiring a single positive charge as a result of electron impact in the source. An example of this type of ion would be the 14 N2+ ion for nitrogen at m/e 28 amu. The molecular ion peak may not always be the peak with the highest intensity in the mass spectrum for a given component. This is especially true for hydrocarbons, where the fragment peaks are usually statistically more likely to occur than the molecular ion. Isotope Ions Isotope ions are produced when one or more of the atoms that comprise a molecule are of a different isotope from that most commonly found. The relative intensities of these ions are defined by the relative abundance of the different isotopic species for the component atoms in question. The relative intensities of isotope peaks are not normally affected by changes in source conditions. An example of an isotope peak is the m/e 29 amu peak observed in the nitrogen mass spectrum. This peak results from a single charge on a nitrogen molecule where one of the two nitrogen atoms is the 15 N isotope. The relative intensity of this peak to the molecular ion at m/e 28 amu is twice the natural abundance of the 15N atom (since the 15 N atom could be either of the two atoms). Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide B-17 Technical Description: System Cracking Patterns Fragment Ions These ions result from fragmentation of the molecule under electron impact in the ion source. In hydrocarbon species these ions are normally the most abundant since longer chain molecules are statistically more likely to be broken. The relative intensities of fragment peaks are dependent on the flux of electrons within the ion source (trap current) and the energy of the electrons from the filament (electron energy). An example of a fragmentation ion would be the m/e 27 amu peak in ethylene. The molecular ion for ethylene has a mass of 28 amu. The 27 amu ion arises from the loss of a hydrogen atom from the molecule. Multiple-Charged Ions These ions result from the sample gas molecule losing more than one electron during the ionization process which gives rise to multiple positive charges. The relative intensities of multiple-charged ions depend upon the energy of the electrons from the filament. It should be noted that multiple-charged isotope and fragment peaks can also occur further complicating the spectrum. An example of a multiplecharged ion peak is the 40Ar++ ion at m/e 20 amu. In some species it is possible to produce ion peaks that are a combination of multiple-charged ions and fragment ions. An example of this would be the m/e 14 amu peak for nitrogen, where the peak is produced from a combination of 14N2++ ions and 14N+ ions. Since the multiple-charged ions have a different energy from the singly charged ions, the observed peak shape resulting from combinations of the two types may be slightly degraded. Rearrangement and Recombination Peaks These peaks arise from a variety of causes, such as ion-molecule interactions within the ion source. The product ions can appear to have strange (and perhaps seemingly impossible) chemical structures. The relative intensities of these ions are usually very low since they normally result from collisions within the ion source between molecules in the gas stream. Relative intensities are very strongly dependent on the partial pressure of the different gas species present, and on the total gas pressure within the ion source. The intensities of these peaks are usually unstable in time and should be avoided for quantitative analytical work. Examples of these types of ions are the m/e 30 amu peak observed in air due to the interaction of nitrogen and oxygen within the ion source to produce NO and the m/e 29 peak observed in methane produced by the interaction of a methane ion with another methane molecule to give a C2H5+ ion at m/e 29 amu. B-18 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Technical Description: System Cracking Patterns Definitions The following definitions are commonly used when defining cracking patterns for a gas species. Base or parent peak: The ion that exhibits the most intense peak in the mass spectrum for that gas species. Cracking fragment: The cracking fragment is given by: C Intensity of the peak for ions of the required m/e  100% Intensity of the base peak for the gas component These are normally expressed in percentages, though some references normalize to 1000. Although this is the most common definition used, the intensities are normalized to the molecular ion rather than to the base peak in some text books and library reference sources. On dual detector systems it is possible that different cracking patterns are observed on the two detectors (and consequently two different cracking patterns stored in the software gas database). These different patterns result from the mass and energy-selective characteristics of the secondary electron multiplier, i.e. the detector has a different gain for ions of different masses and charges. In cases where more than one ion peak is required to identify a component in a mixture with others that have overlapping peaks in their spectra, there is no real alternative to measuring the individual cracking patterns. If a single peak can be used to uniquely identify a species in a mixture then there is little point in measuring a cracking pattern. The system configuration can be set to measure the cracking pattern for a gas species in a given calibration gas bottle by ticking the Fragmentation box for that gas in that bottle (see the Calibration Parameters menu in the software). The cracking pattern for a gas should only be measured in a calibration mixture for which the required ion peaks are unique for the gas species of interest. This is known as a non-overlapping mixture. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide B-19 Technical Description: System Cracking Patterns Table B–4. Example of a cracking pattern for ethylene (C2H4) Mass (m/e) Relative Intensity (%) 2 0.06 12 0.51 13 0.87 14 2.09 15 0.25 24 2.27 25 7.77 26 52.85 27 62.65 28 100.00 29 2.31 It is neither necessary nor recommended to include all of the peaks for a particular gas component. Users should employ the minimum possible number of peaks within the gas database that results in the best conditioning of the sensitivity matrix discussed in the software manual. Examples of application specific calibration gas mixtures and a recommended cracking pattern matrix are normally provided with quotation. B-20 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Appendix C Technical Description: Inlet Rapid MultiStream Sampler Introduction The Rapid Multi-Stream Sampler (RMS) inlet system has been used successfully with a range of Prima and Sentinel gas analysers. The unit selects a single gas stream from a number of incoming sample or calibration gas streams, and some of the selected gas stream is then delivered to the mass spectrometer for analysis. Safety Warning! The notes below must be considered in addition to safety notes elsewhere in this manual covering the system as a whole. Depending on the nature of the gases in use (sample and calibration gases), precautions may need to be taken to avoid inhalation of, contact with, or ignition of these gases. In general, these precautions are as follows.  Always use the correct tubing size for the fittings supplied and the correct nut / ferrule assembly.  Do not exceed the pressure and flow specifications detailed below.  Leak check all external pipe work, and recheck periodically.  Leak check inlet system periodically, as defined in this manual.  Before opening up any gas handling part of the system, it may be necessary to purge the system with a suitable inert or nonhazardous gas. Gas lines and the exhaust line should be isolated. Consideration should be given to the possibility and implications of failure of the isolation mechanism used. Warning! It is the responsibility of the instrument user to assess the potential hazards involved in working on any gas handling parts of the system. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide C-1 Technical Description: Inlet Rapid Multi-Stream Sampler Warning! Before working on the inlet assembly the following points should be noted. Inlet Specification  The inlet is heated at temperatures up to 120°C. Care must be taken to avoid burns.  The inlet contains moving mechanical parts. Movement could start unexpectedly.  Mains voltages exist in the supply to the main heater.  The remainder of the inlet (including the sample tube heater and stepper motor) is driven from a 24 Vdc supply.  In general, it is recommended that the inlet is switched off, the mains and 24 Vdc cables disconnected, and the unit be allowed to cool before carrying out any service work. The following table summarizes the specifications for this inlet system. Detailed discussion can be found in following sections. Table C–1. Inlet system specification Number of inlets 32 or 64 Gas inlet connection (compression type tube fittings) 1/4”, 1/8”, or 6 mm Sample / calibration gas filtration requirement  2 µm Sample gas inlet flow rate (regulated externally) Prima PRO (1) Typical: 0.5 Nl/min Range: 0.1 to 5.0 (2) Nl/min Sentintel PRO Typical: 5.0 Nl/min Range: 2.0 to 10.0 Nl/min Sample gas inlet pressure. Maximum, exhaust blocked to give above typical flow. 0.2 bar(g) (3) Prima PRO: <0.1 bar (4) Sentintel PRO: 0.8 bar(abs) (5) Maximum sample gas / line temperature 200°C Maximum operating temperature 120°C Exhaust requirements Pressure range: 0.8 (3) 1.2 bar(abs) Stability: ±3 mbar/min C-2 (6) Exhaust connection 1" O.D. tube stub Materials exposed to sample gas Stainless steel, Viton, PTFE / graphite Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Technical Description: Inlet Rapid Multi-Stream Sampler composites Number of calibration inlets drives (max) 24 Flushing time required (t99.9% decay time, nonpolar gases) 5 seconds Notes: 1 Gas must be free from liquids or materials that will condense at the operating temperature of the inlet. 2 The total sample flow (i.e. total over all streams) should be considered with respect to the exhaust line, such that back pressure is within the exhaust pressure limits specified above. 3 Limit is to prevent over-pressurisation of and possible degradation in performance of the mass spectrometer. Warning!  Prima PRO Ex applications: The 0.2 bar(g) pressure limit is a requirement of the ATEX/IECEx certification of the instrument and must not be exceeded.  Sentinel PRO Ex applications: The inlets and exhaust must be maintained below atmospheric pressure by using a suction pump connected to the RMS exhaust port. This is a requirement of the ATEX/IECEx certification of the instrument. 4 Pressure relative to exhaust pressure. 5 Higher temperatures may be possible. Consult factory. 6 Suitable for hose or compression fitting, depending on application. Inlet Operation General Description Gas samples connected to the inlet ports are allowed to flow into the common exhaust chamber of the RMS. Process gas samples are typically allowed to flow continuously to minimize the gas response time between the process sample point and the RMS. Calibration gases normally only flow when required (see below). The sample gas streams pass through the inlet ports and enter the RMS common exhaust chamber via a series of holes (connected to the inlet ports) in the RMS main body, or stator (see Figure C–4). A rotary sample arm diverts the flow of one of these sample (or calibration) gases through the sample arm and along an axial sample tube (outer part) to the sample tube main body, which is on the inside of the instrument enclosure. A 2µm screen filter is built into the sample arm (Prima PRO only), so that the selected gas stream is filtered before passing on to the analyser. It should be noted, however, that this is not intended as an active filter, and is only a backup to the main gas conditioning filters installed elsewhere (upstream). It is useful for trapping any debris that may be left over from initial fitting of sample lines. The inlet assembly is attached to a mounting plate, which in turn forms part of the instrument enclosure wall. All of the gas Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide C-3 Technical Description: Inlet Rapid Multi-Stream Sampler connections are on the outside of the cabinet. All electrical, electronic, and moving mechanical parts are internal. Connection to the Mass Spectrometer In the case of the Prima PRO, the selected gas flows around a loop contained entirely within the sample tube body and returns to the main RMS exhaust chamber via the inner tube of the sample tube assembly. A small fraction of the gas in the loop is sampled by the system capillary, which is built in to the sample tube body, and flows on to the mass spectrometer inlet probe via the transfer line. Flow through the capillary is in the range 7 to 10 atm cm3/min, and the pressure in the transfer line is approximately 1 mbar. Compared to the quantity of gas in the sample tube, the flow rate is very high, resulting in a rapid response to sample gas composition changes. Temperature control of the sample tube assembly (see “Heating” later in this chapter) means that flow through the capillary is very stable with minimal dependence on ambient temperature. In the Sentinel PRO, all of the selected gas flows from a port on the sample tube body to the inlet probe where the gas is sampled through a membrane assembly. The excess gas returns to a second port on the sample tube body and is returned to the common exhaust chamber via the inner tube of the sample tube assembly. In both cases, the returning gas passes through an orifice that generates a small pressure difference. A differential pressure sensor is used to measure this difference and thereby give an indication of the gas flow rate. The flow measurement can be used from within GasWorks to generate alarms that can alert to low flow conditions in either sample or calibration gas supplies. Seals The seal between the stator and the sample arm (at the point where the selected sample gas is collected) consists of a spring loaded seal. The spring loading of the seal means that wear is not a significant issue, and no degradation of performance is expected over a period of several years. Furthermore, the flow of the selected gas through the filter, sample arm, sample tube, and pressure sensing orifice generates a slight overpressure within the sample arm. As a result, any leakage at this seal will be out from the sample arm and into the common exhaust. Cross contamination of the selected gas from other streams is thus avoided. The main drive shaft for the sample arm is sealed through the stator by standard rotary shaft seals. These seals have integral spring loading for wear compensation and will give many years of service. The sample tube is sealed within the main shaft by similar (smaller) seals. C-4 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Technical Description: Inlet Rapid Multi-Stream Sampler Inlet Selection The sample arm is driven by a stepper motor connected via toothed pulleys and drive belt. The pulleys are positively mechanically attached to their respective shafts so that slippage is negligible. Inlet position indexing is achieved by optical encoding. An encoder disc is attached to the main drive pulley on the RMS. The encoder is a stainless steel disc with a series of holes close to its circumference, one for each inlet position (the encoder disc has 64 of these holes so, on a 32-way inlet, moving over one inlet position corresponds to moving over two encoder holes). An additional hole (located on a slightly greater circumference) identifies inlet position #1. A pair of optical transmitter / receiver sets is used to sense the individual inlet positions and the inlet #1 position respectively. This type of encoder does not give absolute position indexing. On startup, the main shaft is rotated slowly so that position #1 can be located. To move to other inlets, the controller steps the drive motor to the calculated correct position. At the same time, the second sensor counts the number of inlet positions moved. If there is a mismatch, an error is flagged and the position #1 alignment procedure is repeated. The motion is always clockwise, and position #1 is checked each time the inlet rotates through this point. This procedure has been found to give an extremely high reliability in terms of the accuracy of inlet selection. Calibration Gas Control Calibration gases are expensive and required on a relatively infrequent basis. It would clearly be wasteful to have these gases flowing continuously so additional gas control is required in the calibration gas lines. The main control element is a solenoid valve (24 Vdc, normally closed), located in the calibration gas line before the RMS. The valve is energized (and the gas allowed to flow) by the inlet controller only when the gas is required. The solenoid valves are in manifolds of six valves, the common port from each manifold connecting to a port on the RMS. This means that up to six calibration gases can be handled through one port on the RMS. The manifolds are fitted to the side of the instrument enclosure (up to 4  six way modules as required). This minimizes the line length between the panel(s) and the RMS, which in turn minimizes the flushing time requirement when sampling a calibration gas. The default connection is for calibration gas #1 through #6 to be connected to RMS port 32 (or 64), #7 through #12 to port 31 (or 63), etc. This keeps the low number ports free for sample gas connection (Sample Line #1 can connect to Port #1, etc.). The tubing material used for this connection is FEP. This has excellent chemical resistance and mechanical properties, is non-porous, and has very favourable adsorption and permeation properties. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide C-5 Technical Description: Inlet Rapid Multi-Stream Sampler A restriction element (an orifice) is built into each six-way assembly such that a line pressure of 1.0 bar(g) will give a flow around 150 cm3/min (Prima PRO) or 5 l/min (Sentinel PRO). Fine adjustment of flow is achieved by adjustment of line pressure at the calibration bottle regulator. The incoming calibration gases connect to compression fittings on the bottom of the calibration manifolds(s). By default, the fittings will be the same size / type as fitted to the main RMS body. Gas Connection Sample gases are connected directly to the RMS ports. The connections are compression type. The standard types are 1/4”, 1/8”, and 6 mm Swagelok, but other options may be available. The lines may need to be heated, depending on the gas mixtures to be used. Sample gas flow / pressure should be regulated externally to values within the range indicated in “Inlet Gas Connections” in Chapter 3 (the total flow should also be considered when selecting the exhaust line size). Since the pressure required is quite low, it is preferable to regulate the flow rather than the pressure. In the event of a flow failure, the gas mixture in the common exhaust will diffuse back into that port, and this will be the measured gas if that port is sampled. In order to avoid this (and the possible reporting of false results), the built-in flow sensor is used to verify that flow is within acceptable limits (see “Connection to the Mass Spectrometer”), but note that this can only be used to check the flow of the selected sample stream, i.e. the flow can only be checked when that stream is sampled. External flow monitoring (as part of a sample conditioning system) can also be used and has the advantage that all streams can be continuously monitored, but does require a flow monitor for each sample line. Gases must also be conditioned to remove particulate material down to 2 µm. Liquids or materials that could condense at the operating temperature of the RMS should also be removed. Consideration should be given to fault conditions that may occur in the process or sample lines and maximum and minimum ambient temperatures to which the sample lines and RMS may be exposed. C-6 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Technical Description: Inlet Rapid Multi-Stream Sampler Exhaust Connection The exhaust connection is a 1" O.D. tube stub, suitable for a simple hose connection or a compression fitting depending on application. It may be required to heat the exhaust line. This can be just as critical as the sample lines but is often neglected. Alternatively, the exhaust line can be configured with a continuous downward slope so that any condensate will drain away from the valve. If this is not possible, a trap should be installed to prevent condensate draining back to the RMS. The exhaust line size should be selected, giving consideration to the maximum total sample gas flow, and the length of the line. The requirement is to generate a negligible back pressure, as any such back pressure will be flow dependant and may result in variable conditions at the analyser. For an application where there are a limited number of sample lines or the lines are all low flow, it may be possible to reduce the line size to 1/2” for example. At the other flow extreme, it may be necessary to adapt up to a line size greater than 1". The pressure at the exhaust should be within the values specified in “Inlet Specification”. Any pressure variation will result in a variation at the analyser, so the pressure stability should also be within specified limits. Longer term variations outside this range may be acceptable but will require more frequent instrument calibration. The easiest way to achieve the required stability is to use a direct atmospheric vent. However, this is not always possible depending on the nature of the gas mixture, local environmental regulations, etc. An alternative, such as a line to a flare, may be used if the above conditions can be met. If the exhaust line is shared with other equipment, consideration should be given to pressure fluctuations that might be caused by that equipment. In conditions where all sample streams to the RMS are off, the possibility of back diffusion of gases from the exhaust must also be considered. For this reason, extreme care must be taken if the analyser rotary pump is vented to the same exhaust system. The pump exhaust will contain oil vapour that could contaminate the RMS and subsequently the mass spectrometer. Where possible, it is preferable to avoid such a connection. In some cases, it may be necessary to use a pump to produce a negative pressure at the RMS exhaust to induce flow in the sample lines particularly when sample points are at low pressures. This is the normal operating mode for the Sentinel PRO. Clearly, the pressure (vacuum) generated by any such pump should conform to the above requirements. It is important to remember that all sample gases are mixed in the common exhaust. There may be situations where combustible or reactive mixtures are generated. To avoid problems of this nature, a diluting gas (commonly nitrogen) can be added to the exhaust line or Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide C-7 Technical Description: Inlet Rapid Multi-Stream Sampler via spare RMS ports (the latter may be more convenient if spare ports are available). Heating The inlet assembly can be heated to 120°C to avoid condensation, polymerization, etc. of sample gas mixtures. Two heaters are required to heat the main body and peripheral parts of the inlet as follows. Control of the heaters is discussed later in this chapter. Main Body Heater The bulk of the inlet body is maintained at the required temperature by the use of one of two possible types of heater: a. A ring heater clamped to the RMS stator on the enclosure side. The heater has two windings with a common connection, such that a three-wire connection is required. b. Cartridge heaters (4-off) located in bores in the stator itself. The four heaters are wired to mimic case (a), i.e. effectively a twin element assembly, with a three-wire connection. The three-wire connection allows for series or parallel connection for 230 V or 115 V applications respectively, selected by a switch on the inlet controller PCB. Insulation is provided to minimize heat loss into the enclosure. A K-type thermocouple is used to measure and thereby control the temperature of the valve body via the control electronics. A thermal switch assembly trips off the heater at a body temperature of 140°C in the event of a runaway condition. Sample Tube Heater The sample tube body carries the selected gas stream flow and so also requires heating. A 30 W, 24 V cartridge heater heats the sample tube body, and a PRT is provided for measurement and control. Typically, this assembly is set to the same temperature as the main body. Additional temperature limiting is not required as the heater power is insufficient to take the assembly to a dangerous temperature. The actual sample tube between the sample tube body and the valve body is clad in copper, which greatly improves the thermal conductivity and helps maintain a uniform temperature along its length. Gas Flow versus Temperature The above heaters were specified assuming that the incoming sample gases are heated to a temperature similar to that set for the RMS. However, there may be situations where this is not the C-8 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Technical Description: Inlet Rapid Multi-Stream Sampler case. For instance, all streams may be cold (a common situation for Sentinel PRO applications), or there may be a combination of hot and cold streams. Consideration must be given to the possible general cooling of the RMS body or to localized cooling – for example, the cooling effect of a cold gas flow on an adjacent port or the cooling of the common flow regions (sample tube, etc.). The latter could be important if a cold stream is sampled immediately prior to sampling a temperature critical hot stream. The following examples illustrate the limits of cold gas flows (the cold gas streams are assumed to be air or nitrogen at a temperature of 20°C). a. To maintain a body temperature of 80°C, the maximum cold gas flow is 500 Nl/min. b. To maintain a body temperature of 120°C, the maximum cold gas flow is 250 Nl/min. c. A cold gas flow of 10 Nl/min on a single port (the maximum allowed) will cool an adjacent port by approximately 4°C. d. A cold gas flow of 10 Nl/min on a single port (the maximum allowed) will cool the sample tube by approximately 10°C (over a period of several minutes). Similarly, the temperature takes several minutes to recover. This situation can be avoided by reducing the cold gas flow rate or bypassing approximately 80% of the cold stream to a spare (nonsampled) RMS port. Potential problems can be minimized by careful selection of which ports hot and cold gas streams are connected to and the sequence of sampling of these ports. Hazardous Area Systems Details of the protection methods used for hazardous area operation, both for the system as a whole and specifically for the RMS, are given in Appendix A: Hazardous Area Operation. An important point relating to hazardous area operation of the RMS is that it must be possible to predict in a fault condition the maximum leak rate of any sample into the enclosure. The sample pressure therefore defines the flow rate through any leak, and the upper pressure limit for the Prima PRO Ex of 0.2 bar(g) must be strictly adhered to and forms part of the hazardous area certification for the instrument. For the Sentinel PRO Ex, samples are maintained under reduced pressure by virtue of the sample pump, which in turn prevents any possible leakage into the enclosure. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide C-9 Technical Description: Inlet Rapid Multi-Stream Sampler Inlet Controller General The inlet controller handles all the control functions required for the RMS and its associated calibration panels. The controller PCA is mounted on the left hand side of the enclosure below the inlet assembly. Most connections are via pluggable screw terminals. The RMS sampling head drive is unidirectional and indexed at port 1 every rotation (see “Inlet Operation”). The controller drives the sample arm to port 1, which is indicated by both the red and the green LED being illuminated on the sensor PCB. If the reference aperture cannot be found, the controller will stop searching after 60 seconds. The sample arm completes any port to port transit in less than two seconds. Positioning failure (due to mechanical or electronic failure) is communicated to the inlet controller and the unit will re-index on the next commanded move. The controller is powered from the main enclosure power supply (24 Vdc). Mains power is required for the main body heater (see below). Fuses (all on PCB): F1: 5 A (mains) F2: 1 A (24 Vdc, calibration gas valves). Supply OK indicated by green LED D2. F3: 4 A (24 Vdc, all other functions). Supply OK indicated by green LED D19. A watchdog function is used to show that the processor is active (red LED D6). Calibration Valve Drives There are 24 outputs, individually addressable with up to 4 switched on at any one time (limited in software). Each is designed to deliver up to 300 mA at 24 Vdc and is intended to drive a single calibration gas control solenoid valve. Main Body Heater Mains power is connected to J18 along with the heater(s) and overtemperature thermal switch. This allows 115 Vac or 230 Vac operation to be selected by means of a switch on the PCB. Unplugging J18 or switching off the Inlet circuit breaker in the main enclosure will remove mains power from the PCB. Warning! Removal of F1 will only break the L/L1 line. Power might still be on the assembly from the N/L2 line.  C-10 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Technical Description: Inlet Rapid Multi-Stream Sampler The main body thermocouple connects to J13. Power to the heater is switched via a solid state relay on the PCB, giving a control precision of ±1°C, accuracy ±3°C. A red LED (D25, adjacent to the solid state relay) flashes when the RMS body heater is driven on (if the heater is not driven on at all, i.e. the RMS body temperature is above the set point, the LED alone is driven on for 10 ms every second). Sample Tube Heater Flow Sensor The sample tube PRT connects to J15 and the heater output (24 Vdc) to J16. Control precision is ±1°C, accuracy ±3°C. A red LED (D24) flashes when the sample tube heater is driven on. Connect the flow sensor to J17. Digital Inputs Four opto-isolated digital inputs are available (J5, J6, J9, J10). Generally, these are used for internal monitoring of inlet functions (e.g. sample vacuum sensor for the Sentinel PRO). They can be configured as requiring 24 Vdc or voltage free contact input by means of jumpers on the PCB. A red LED adjacent to each connector indicates the status of the input. VGiNet The red LED adjacent to the VGiNET sockets (D3) indicates data received by the unit (not necessarily for it or processed by it) and the green LED (D4) indicates data transmitted from it. When the unit detects a message intended for it, it will respond with a reply message and so a full message cycle will appear as a red flash followed quickly by a green flash as the reply is transmitted. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide C-11 Technical Description: Inlet Rapid Multi-Stream Sampler Inlet Testing Testing of the inlet system may be required in order to confirm correct performance, in the event of unexpected analytical results, suspected contamination, or following a major service. The areas to be checked are as follows. It is advisable to switch off the inlet heaters before starting any work. Caution! Functional Testing  Before starting any work, switch off all gas lines.  If required, the system should be purged with a suitable inert, safe gas and the system exhaust isolated.  It is the responsibility of the user to assess the hazard involved in breaking into any gas handling part of the system. Inlet Alignment Remove the stator cover from the RMS body. Warning!  Possible gas hazard. See Chapter 2: Safety Information.  Moving mechanical parts exposed. Movement could start unexpectedly.  Hot surfaces. Check RMS temperature settings before starting work. Adjust as required. Select a port using GasWorks (Control Centre > Analogue Scan, etc.). Check that the sample arm moves to the correct physical port and check that the sample arm is aligned over that port. It should be (visually) equally spaced between the two adjacent ports. A slight misalignment can be corrected by loosening the four screws retaining the sample arm to the main shaft and moving the arm to the correct position before retightening. Check several ports, including #1, in this way. The probability of the inlet operating with no reported errors but giving significant mechanical misalignment is extremely low as all parts are mechanically keyed together. Check that the main pulley is secure on the drive shaft and that the sample arm is aligned with the position #1 cutout on the encoder disc (incorrect reassembly after servicing could result in 90°, 180°, or 270° misalignment). If the controller reports positional errors, check if position #1 can be located correctly. If it can, but subsequent inlets are showing C-12 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Technical Description: Inlet Rapid Multi-Stream Sampler errors, there may be a motor or driver fault (or, very unlikely, a mechanical fault making the shaft difficult to rotate). If position #1 cannot be located (the motor drives slowly as it searches for position #1) then the most likely cause is a problem with the optical encoder. There are two LEDs on the encoder PCB. The green one is lit whenever the RMS is “on” an inlet. The red LED indicates position #1 (i.e. both LEDs will be lit at position #1). For ease of checking the functionality of the optical sensors, the RMS can be rotated by hand: switch off the controller, unplug the motor connector, and switch back on. If there appears to be a problem, check that there is no dust around the holes in the disc and around the optical transmitters / receivers. If there is no activity, remove the screws fixing the encoder disc to the pulley (note the orientation). Both LEDs now should be lit. Slide a piece of paper between the optical transmitters and receivers, and both LEDs should be off. If it appears that the LEDs (and hence the optical sensors) are working correctly, then the bracket holding these sensors may need adjustment. Refit the encoder disc. Loosen the nuts holding the bracket in place and adjust until both LEDs are on at position #1 (Adjustment will affect the alignment of the sample arm with the port. Remember that the arm position can be adjusted slightly, as noted above). Switch off, reconnect the motor, and switch on. Check that alignment is still OK when the motor is driven. Check a selection of other ports. Heating If there is a reported fault, the following checks can be carried out. Main Heater Warning!  Mains voltages present.  Switch off at the Inlet circuit breaker before removing the inlet controller PCA cover or disconnecting any heaters. Verify that the temperature readout is correct. Use an independent temperature measurement if required. Check F1 on the controller and then check that the controller is delivering power to the heater connections on the controller (J18) (This may not be a continuous supply if the controller is attempting to control. See also “Main Body Heater”). Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide C-13 Technical Description: Inlet Rapid Multi-Stream Sampler Check the status of the heater and thermal trip by disconnecting at J18. The wires (1-5) from the heaters and trip are:  Wire 1: Heater 1  Wire 2: Heater common  Wire 3: Heater 2  Wire 4 & 5: Thermal trip The electrical resistance between wires 4 and 5 should be approximately 0 Ω, unless the RMS body is over temperature or the thermal trip is faulty. The resistance between wires 1 and 2 and between 2 and 3 should be the same – around 140 Ω for a system with cartridge heaters, either 70 Ω or 35 Ω (depending on type) for a ring heater system. Sample Tube Heater Verify that the temperature readout is correct. Use an independent temperature measurement if required. Unplug the heater and check the heater resistance. The standard heater should be approximately 19 Ω. Reconnect the heater, and switch on the voltage across the heater. It should be 24 Vdc. Check fuses if required voltage is not present. Cross Port Leakage This test should be carried out with the stator cover fitted. Set up a continuous flow of air on one or more ports (flow within the specified limits) and a helium flow on another port. (The helium flow does not need to be a continuous flow and can be a calibration port. Helium should flow at typical calibration gas flow rates.) Sample the air inlet and measure the mass 32 peak height. Next, sample the helium inlet and check that the mass 32 peak height drops by the required factor (for a Prima PRO the factor is system pressure (mbar)  108, and for a Sentinel PRO the factor is 200). If it is not possible to introduce air into the system, the test should be carried out with process gas flowing. Measure the peak heights of masses in the analysis and check against historic values (e.g. from a calibration report from when the instrument was initially installed). Backgrounds should be similar to the original values. If the inlet fails to meet specification, follow the procedures for inspection and / or replacement of seals detailed later in “Maintenance”. C-14 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Technical Description: Inlet Rapid Multi-Stream Sampler External Leakage A limited amount of leak checking can be carried out with process gasses connected and flowing e.g. leak checking of external connections using a proprietary bubble type leak detector, such as Snoop. It should be noted that the pressure in the RMS body may be low or below ambient and it is very difficult to test rotary seals by this method. The best method involves a positive pressure test. Isolate or disconnect / plug all sample lines and the exhaust line (3˚C )between Gasworks & air con temperature readouts, not controlling Possible c Cabinet temperature not cycling and reading low c Cycling time >6 minutes Possible c (intermittent) Liquid (water) in condensate drain tube to instrument enclosure None Prima PRO & Sentinel PRO Mass Spectrometers User Guide Refrigerant charge low required. System designed for temperatures up to 40˚C max. Check status when powered off & cool. If still in alarm, this suggests a pressure switch fault. Check for leaks. Refill, as per specification on air conditioner label. Pressure switch fault Internal fan failure Check internal fan – should be running continuously. If not, check supply and if fan can be rotated freely. Compressor Check compressor operation failure (e.g. vibration, total current drawn). Fault in air con Check mounting of sensors to sensor or air con grille. controller Check sensor connections. Check response of sensors to Fault in forced temperature changes e.g. instrument hand heat. sensor or readUse an independent temperature back via ASU measuring device to determine which is correct. Cooling Check operation of temperature continuously, controller output contacts – not regulating these may not be switching correctly. Check bypass valve – coil resistance (not open circuit) and supply (should be on when temperature below set point) Bypass timeout Check if compressor is operating switching off in each cycle. Possible temperature controller fault. Air con being Switch off air conditioner when operated with door is open for any significant enclosure door time (depends on ambient open humidity). Enclosure purge Use instrument grade air with a air has too high suitable known dew point. water content Thermo Fisher Scientific Appendix F Regulatory FCC Federal Communications Commission Radio Frequency Interference Statement. Information to the user: Warning! This device complies with Part 15 of the FCC rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) This device must accept any interference received, including interference that might cause undesired operation. This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at their expense. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide F-1 Regulatory WEEE WEEE European Union Waste Electronic & Electronic Equipment Directive. This product is required to comply with the European Union’s Waste Electrical & Electronic Equipment (WEEE) Directive 2002/96/EC and is marked with the following symbol: This product contains electronic parts and assemblies and should be disposed of at end of useful life in an appropriate and responsible manner. Thermo Fisher Scientific has contracted with one or more recycling / disposal agencies in each EU Member State, and this product should be disposed of or recycled through them. For further information, contact your distributer or reseller in the country of use. In the UK, contact Thermo Fisher Scientific, Ion Path, Road Three, Winsford, CW7 3GA. F-2 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific Regulatory China RoHS China RoHS Toxic & Hazardous Substances Table – Prima PRO / Sentinel PRO (Safe Area & Ex). For Chinese Regulation: Administrative Measure on the Control of Pollution Caused by Electronic Information Products. Names and Content of Toxic and Hazardous Substances or Elements. Thermo Fisher Scientific Prima PRO & Sentinel PRO Mass Spectrometers User Guide F-3 Regulatory China RoHS F-4 Prima PRO & Sentinel PRO Mass Spectrometers User Guide Thermo Fisher Scientific