Marking of pressure sensors and transmitters according to ATEX Guideline 94/9/EC ? how exactly to read the ATEX label on pressure sensors

If pressure sensors, pressure transmitters and other field equipment are used in the vicinity of flammable gases or dust, they might be subject to marking in accordance with the ATEX product guideline 94/9/EC. Brutal requires the sort label of the sensor to include the ATEX marking, so usually this is labelled directly onto the sensor during production.
Next to the Notified Body and the approval number, the marking of pressure sensors also contains important information for an individual. For example, an ?X? following the approval number indicates that special conditions must be observed when using the device. These are either given in the approval document and in the corresponding manual. Above all, marking in accordance with ATEX gives information on the possible areas of application and the type of protection useful for the pressure sensor:
Explosion group:
I Mining industry, II the areas useful Device class:
Use 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 near flammable gases (3G), dust (3D)
However, there are also devices where only certain parts may be installed in other zones, for instance, a pressure sensor marked 1/2G could be installed in a tank with flammable content. Unadulterated of the transmitter is located on the outside of the tank, and therefore 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, suitable for zone 2/22 m
encapsulation suitable for zone 1/21 and 2/22 Gas group and temperature class: i.e. IIC T1 for hydrogen
Note:
Further information about hydrogen are available on the WIKA website. In case you have any more questions, your contact will gladly assist you to.

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