The bench for testing and certification of differential circuit breakers, named SOF_OHM, is based on the detection and sampling of the trip current of the devices under test in order to evaluate the waveform in terms of amplitude and duration.

The test is run by a dedicated software program which controls the sequence of activation of a resistor bank, the off-the-shelf instrumentation, the consequent mathematical analysis of the waveform, the output of the results.