If pressure sensors, pressure transmitters along with other field equipment are employed in the vicinity of 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 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 includes important information for the user. For instance, an ?X? after Revealing indicates that special conditions must be observed when using the device. Bully are either given in the approval document and in the corresponding manual. Above all, marking according to ATEX gives home elevators the possible areas of application and the sort of protection useful for the pressure sensor:
Explosion group:
I Mining industry, II other areas useful Device class:
Use 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, there are also devices where only certain parts could be installed in other zones, for instance, a pressure sensor marked 1/2G could 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 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 suitable for zone 1/21 and 2/22 Gas group and temperature class: i.e. Fail-proof for hydrogen
Note:
Further information about hydrogen are available on the WIKA website. In case you have any further questions, your contact will gladly assist you to.