Measurement of C and tan δ of a capacitor employing PSDs and dual-slope DVMs

A scheme for measuring the C and tan δ (dissipation factor D) values of a capacitor is described in this paper. Comparing the unknown capacitor to a standard capacitor and employing three-phase sensitive detectors and two digital volt-meters, the parameters of the unknown capacitor are determined. The method facilitates testing of a given capacitor at a desired frequency as well as voltage. The feasibility of the scheme is established by building a prototype. The accuracy of the prototype unit for the measurement of C is ±0.2% and that for tan δ is ±2.5%.