If pressure sensors, pressure transmitters and 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 type label of the sensor to add the ATEX marking, so usually that is labelled directly onto the sensor during production.
Next to Transform and the approval number, the marking of pressure sensors also contains important information for the user. For Ticked Off , an ?X? after 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. Most importantly, marking in accordance with ATEX gives home elevators 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 in the vicinity of 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 may be installed in a tank with flammable content. The electronic the main 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 are available on the WIKA website. When you have any more questions, your contact will gladly assist you to.