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

If pressure sensors, pressure transmitters and other field equipment are used near flammable gases or dust, they might be subject to marking relative to the ATEX product guideline 94/9/EC. ATEX 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 Hurry and the approval number, the marking of pressure sensors also contains important information for the user. For example, an ?X? after the approval number indicates that special conditions must be observed with all the device. These are either given in the approval document and in the corresponding manual. Above all, marking in accordance with ATEX gives info on the possible regions of application and the type of protection useful for the pressure sensor:
Explosion group:
I Mining industry, II other areas useful Device class:
Used in zone 0/20 in the vicinity of von flammable gases (1G), dust (1D)
Used in zone 1/21 in the vicinity of flammable gases (2G), dust (2D)
Used in zone 2/22 near flammable gases (3G), dust (3D)
However, additionally, there are devices where only certain parts could be installed in other zones, for instance, a pressure sensor marked 1/2G may be installed in a tank with flammable content. The electronic portion of the transmitter is located externally of the tank, and thus in zone 1.
Examples for types 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, ideal 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. Strongly Suggest for hydrogen
Note:
Further information on the subject of hydrogen can be found on the WIKA website. In case you have any more questions, your contact will gladly help you.

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