For most non-voltage-producing devices located in a hazardous area, a single Zener Barrier that is negative-earth-grounded can be used for intrinsic safety. Instrumentation that produces an output (signal conditioners) usually requires two barriers, one for each "floating" lead. In this case, a dual channel barrier can be provided.
Or, for applications where the instrument signal return level cannot be reduced, a supply barrier and a low resistance return barrier can be supplied (shown below).
For floating leads: 65800 Series supply and return barriers for signal conditioners.
Installation and maintenance must be in accordance with the National Electrical Code and the applicable Gems Instruction, Installation and Service Bulletin available at gemssensors.com