An Automated Permuting Capacitor Device for Calibration of IVDs

A new automated permuting capacitor device (APCD) for calibration of inductive voltage dividers (IVDs) with four-terminal-pair definition was designed and tested. The permuting capacitors composed of 11-SMD capacitors were housed in a bulk metal in a symmetrical arrangement. Thus, the APCD is compact and the temperature of the APCD could be controlled within several mKs. Using coaxial microwave switches, the APCD was permuted quickly and automatically using electrical signals during the calibration process. This prevented the APCD from being thermally perturbed by manual operation. Owing to the improved stability of the device, the effects of stray capacitance and voltage coefficient of the APCD were evaluated accurately. The calibration of an IVD using the permuting capacitor method with this APCD in the frequency range 1-2 kHz with accuracy comparable with that of the straddling method is presented in this paper.