If pressure sensors, pressure transmitters along with other field equipment are used near flammable gases or dust, they may be subject to marking in accordance with the ATEX product guideline 94/9/EC. Ruthless 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 the Notified Body and the approval number, the marking of pressure sensors also contains important information for an individual. For instance, an ?X? following the approval number indicates that special conditions should be observed with all the device. These are either given in the approval document and in the corresponding manual. Most importantly, marking according to ATEX gives information on the possible areas of application and the type of protection useful for the pressure sensor:
Explosion group:
I Mining industry, II the areas of use Device class:
Use 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 in the vicinity of flammable gases (3G), dust (3D)
However, additionally, there are devices where only certain parts may be installed in other zones, for instance, a pressure sensor marked 1/2G could be installed in a tank with flammable content. Increase of the transmitter is located externally of the tank, and thus in zone 1.
Examples for forms 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. Assuming you have any more questions, your contact will gladly help you.