Marking of pressure sensors and transmitters in accordance with ATEX Guideline 94/9/EC ? how exactly to browse the ATEX label on pressure sensors

If pressure sensors, pressure transmitters and other field equipment are employed near flammable gases or dust, they might be subject to marking in accordance with the ATEX product guideline 94/9/EC. ATEX requires the type label of the sensor to include the ATEX marking, so usually that is labelled directly onto the sensor during production.
Close to Unadulterated and the approval number, the marking of pressure sensors also contains important information for an individual. For instance, an ?X? following the approval number indicates that special conditions should be observed when using the device. These are either given in the approval document and in the corresponding manual. Most importantly, marking in accordance with ATEX gives info on the possible regions of application and the type of protection used for the pressure sensor:
Explosion group:
I Mining industry, II the areas useful Device class:
Used in zone 0/20 in the vicinity of von flammable gases (1G), dust (1D)
Use in zone 1/21 near flammable gases (2G), dust (2D)
Use in zone 2/22 in the vicinity of flammable gases (3G), dust (3D)
However, there are also devices where only certain parts may be installed in other zones, for example, a pressure sensor marked 1/2G may be installed in a tank with flammable content. The electronic portion of the transmitter is located on the outside of the tank, and thus in zone 1.
Examples for forms of protection:
i intrinsic safety (Limitation of electrical ignition energy by limiting current and voltage)
ia for Zone 0 or Zone 20 (for Zone 20 also iaD)
ib for Zone 1 or Zone 21 (for Zone 21 also ibD)
ic for Zone 2 d
flameproof / explosion proof enclosure, suitable for zone 1/21 and 2/22 n
non-incendive, ideal for zone 2/22 m
encapsulation ideal for zone 1/21 and 2/22 Gas group and temperature class: i.e. IIC T1 for hydrogen
Note:
Further information on the subject of hydrogen are available on the WIKA website. If you have any further questions, your contact will gladly assist you to.

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