DrägerSensor® & Portable Instruments Handbook 2nd Edition Draeger / Drager  (click on the title to view the complete article)

This handbook is intended to be a reference for the users of DrägerSensors and portable gas detection.

Properties of dangerous gases and vapors

Flammable and toxic gases and vapors occur in many areas. It is important to recognize the danger they pose – and that is the purpose of gas detection and warning devices.
This handbook is meant to give a basic introduction to gas detection technology, measuring principles and safety concerns.

Ideal Gas Law

– At a constant pressure, volume of gas changes in proportion to their temperature –their volume increases when heated;
– If the volume remains the same (for example, in a closed container), then the gas pressure changes in proportion to their temperature – for example, the pressure inside
a container increases when heated;
– At a constant temperature, pressure changes inversely proportion to volume –for instance, the interior pressure rises when gas is compressed.

Requirements for gas detection instruments

As safety products, gas detection devices for industrial use must fulfill the statutory requirements (explosion protection, electromagnetic compatibility), as well as other
requirements, so that their quality and reliability remains assured even under tough conditions.

Explosion protection standards:
Design stipulations ensure that the gas measuring instrument does not become a source of ignition itself. Globally accepted standards include CENELEC (ATEX), CSA, UL, GOST, etc.
Protection ratings as defined by EN 60529 (IP Code)
The IP code provides information about the degree to which a casing provides protection against foreign objects and water.