Verification of partial discharge calibrators

The paper deals with an impulse charge measurement in the range from few pC to tens of nC with higher accuracy. An impulse charge is usually generated by calibrators of partial discharge measurement instruments. The charge value is determined from recorded impulse current as voltage drop on sensing resistor, which loads the calibrator. The resulted charge, which is generated by calibrator, is then evaluated as numerical integration of impulse current. Some results of numerical integration using digital scope and direct sampling by 14-bits digitizer with sampling frequency of 200 MSa/s are presented in the text. The investigation of measurement uncertainty is presented as well.