Intrinsically safe binary isolators transfer the signal state from the explosion-hazard zone to the galvanically isolated state of the output relay on the safe side. The devices are ATEX certified. Galvanic isolation of the circuits protects sensitive industrial automation systems (e.g., PLC controller cards) from the dangerous effects of overvoltages or lightning strikes and reduces the impact of object interference.
These devices can also be used to monitor the input circuit. In the event of a short circuit or open circuit, the output state of the alarm relay will change.
Information about the input signal status is signaled via a relay or opto-relay (depending on the switching frequency).
The intrinsically safe input circuit can cooperate with an intrinsically safe circuit with protection level ia or ib of a device installed in a group I explosion hazard zone and zones "0, 1, 2, 20, 21, 22" of group II of any mixtures.
The input signal can be:
  - contact, OC transistor
  - current, e.g. NAMUR (1.2/2.1mA),
  - voltage, e.g. 0/24V, TTL, CMOS,
  - proximity sensor, turbine flow sensor, etc.