METHOD TO MEASURE INSULATION RESISTANCE OF DC CIRCUITS UNDER OPERATING VOLTAGE AND DEVICE FOR ITS REALISATION Russian patent published in 2014 - IPC G01R27/18 

FIELD: electricity.

SUBSTANCE: in the intervals between measurements of insulation resistance they control measurement channels by connecting inputs of the first measurement channel to a single point and determining the mean value of "zero" after "n" measurements to account in the calculation of voltage and then connect these same inputs to both poles of the controlled circuit for the subsequent calculation of the ratio of secondary (from "n") values, which are for the second channel to the average value of the first channel, the output calculated indicators beyond preset thresholds conclude inappropriate functioning of the measurement channels, and otherwise the subsequent calculation of the total resistance of insulation is according to the formula:.

EFFECT: improving immunity and measurement accuracy simplification of a device using the claimed method, enhanced functionality through implementation of self-test function of channels and devices in general.