They are devices that isolate the input/output with the compliance and certification for isolating intrinsically safe sensor signals relative to the security zone.
Unlike las barreras zener, insulating behaviour does not depend on the presence or quality of the grounding installation. This advantage allows us to use in facilities where it is not possible to have a good grounding and avoid major problems caused by poor returns on land connections.
The signals that are applied are analogic if we have the model IRU-240H from our DINEL, which is specially designed for isolation of transmitters of 4-20 mA with HART protocol.
The IRU series is completed with two specific models, both with 4-20 mA input and repetition output of the 4-20 mA or conversion to 0 to 10 Vdc.
Another option is the model ST 500 EX MARTENS, which isolates signals 0-20 mA, 4-20 mA and 0 to 10 Vdc. The power can be 230 Vac or 10 to 30 V ac / dc.
MARTENS also offers the MU series 500 EX equivalent to the ST but for temperature signals with PT100 or PT1000 and output 0 to 20 mA, 4 to 20 mA or 0 to 10 Vdc.
It is important to mention the amplifier relays NAMUR that offers an universal and free of voltage relay from a contact EX (NAMUR) ready to be installed in the safe zone.