If pressure sensors, pressure transmitters along with other field equipment are used in the vicinity of flammable gases or dust, they might be subject to marking relative to the ATEX product guideline 94/9/EC. Doomed requires the type label of the sensor to include the ATEX marking, so usually this is labelled directly onto the sensor during production.
Close to Foul and the approval number, the marking of pressure sensors also includes important information for an individual. For instance, an ?X? following 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 according to ATEX gives home elevators the possible regions of application and the sort 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 near 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 example, a pressure sensor marked 1/2G could be installed in a tank with flammable content. The electronic section 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, suitable for zone 1/21 and 2/22 n
non-incendive, suitable 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 about hydrogen can be found on the WIKA website. For those who have any more questions, your contact will gladly assist you to.