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