If pressure sensors, pressure transmitters and other field equipment are used 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 sort label of the sensor to add the ATEX marking, so usually that 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 the user. For example, 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. Above all, marking in accordance with ATEX gives info on the possible regions 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 near von flammable gases (1G), dust (1D)
Used in zone 1/21 in the vicinity of 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 example, a pressure sensor marked 1/2G may be installed in a tank with flammable content. Faith of the transmitter is located externally of the tank, and therefore 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, ideal 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. When Exactly have any further questions, your contact will gladly assist you to.g