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

If pressure sensors, pressure transmitters along with other field equipment are used in the vicinity of flammable gases or dust, they may be subject to marking in accordance with the ATEX product guideline 94/9/EC. ATEX requires the sort label of the sensor to add the ATEX marking, so usually that is labelled directly onto the sensor during production.
Close to the Notified Body 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 should be observed when using the device. These are either given in the approval document and in the corresponding manual. Above all, marking according to ATEX gives info on the possible areas of application and the type of protection used for the pressure sensor:
Explosion group:
I Mining industry, II other areas useful Device class:
Used in zone 0/20 near von flammable gases (1G), dust (1D)
Used 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 section of the transmitter is located externally of the tank, and therefore 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, 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. Unbelievable for hydrogen
Note:
Further information on the subject of hydrogen can be found on the WIKA website. In case you have any further questions, your contact will gladly assist you to.g

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