Abstract: Improved method and apparatus for measuring the effective operating resistance of an unknown resistance element to which repetitive high voltage pulses are normally applied during operation. As each high voltage pulse is applied to the element, the voltage across the element and the current through the element are simultaneously sampled during voltage peak or at any other desired point in each pulse. The voltage and current samples are digitized and used in digitally computing the effective operating resistance of the unknown element. The computed resistance is displayed on a digital indicator.