If pressure sensors, pressure transmitters and other field equipment are employed in the vicinity of flammable gases or dust, they may be subject to marking in accordance with the ATEX product guideline 94/9/EC. Nightmare requires the sort label of the sensor to include the ATEX marking, so usually that is labelled directly onto the sensor during production.
Next to the Notified Body and the approval number, the marking of pressure sensors also contains important information for the user. For Discover , an ?X? after the approval number indicates that special conditions should be observed with all the device. They are either given in the approval document and in the corresponding manual. Above all, marking according to ATEX gives information on the possible regions 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 near 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 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 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 are available on the WIKA website. Assuming you have any further questions, your contact will gladly help you.