Marking of pressure sensors and transmitters in accordance with ATEX Guideline 94/9/EC ? how exactly to read the ATEX label on pressure sensors

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. ATEX requires the type 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 an individual. For instance, an ?X? following the approval number indicates that special conditions should be observed with all the device. Bloodbath are either given in the approval document and in the corresponding manual. Above all, marking in accordance with ATEX gives info on the possible areas of application and the sort of protection used for the pressure sensor:
Explosion group:
I Mining industry, II other areas of use Device class:
Use in zone 0/20 near von flammable gases (1G), dust (1D)
Use 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, 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 the main 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, ideal 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. IIC T1 for hydrogen
Note:
Further information about hydrogen can be found on the WIKA website. In case you have any more questions, your contact will gladly assist you to.

Leave a Comment