Atex Certification for Hazardous Area

Depends...

https://www.controldesign.com/articles/2019/are-purged-enclosures-and-intrinsically-safe-barriers-necessary/

Thanks sir, it is useful

but lets be more specific if you don't mind, we have 2 pressure Transmitters installed in zone 2 area (they are certified for Zone 2 installation), those transmitters connected thru cable to field junction box certified for zone 2 (i.e. Exd proof). then one homerun cable goes to PLC room (Non hazardous area), do we need in this case to use I.S barrier before termination to PLC I/O card?

Thx

I wouldn't think so, the PLC cable is low voltage intrinsically safe, is it not?

https://www.mtl-inst.com/images/uploads/datasheets/App_Notes/AN9003.pdf

When looking at barriers for hazardous zones you also need to take into account any energy that might be stored in the cable. Cable faults outside your certified equipment can release enough energy to create a spark and ingnite the gas so minimize your cable lengths and select the L/R ratio of your cable according to the regulations.