METHOD TO MEASURE LOW RESISTANCES, INCLUDING DRAIN-SOURCE RESISTANCE OF FIELD TRANSISTOR OPEN CHANNEL Russian patent published in 2012 - IPC G01R27/00 

FIELD: electricity.

SUBSTANCE: invention relates to measurement of field transistor open channel drain-source resistance (FTOCDSR), however, it also makes it possible to measure low resistances (R) of shunts, contacts of switches and other media with low R. The method includes sending an available current (AC) through the FTOCDSR with subsequent indication without scaling or with scaling of a voltage drop (VD) on it. At the same time a protection of an input measurement circuit against overload is introduced, during switchovers of measurement ranges or unavailability of a measured object. Within the specified measurement range the identified VD with the help of selecting, manually or automatically, the available R, a plug resistance (PR) or a current digital to analog converter, is converted into a current of a preset value multiple to AC. Then or directly the readings are taken from the PR or via analog to digital conversion with the present current from the reference voltage the readings of measurement values are induced, multiple to the value of the measured R.

EFFECT: higher accuracy of measurement with acceptable power consumption and higher reliability of measurement elements and a metre in a potable version.

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