Improvement of High-Value Capacitance Measurement

An improved method of measuring high-value capacitors based on sampling technology is presented in this letter. A standard resistor is used as reference at its resistance and time constant. An inductive shunt is used to produce two precisely equal currents in parallel so that the capacitor and the resistor can be measured at ground potential. The calibration procedure for the inductive shunt, the measured results, and their uncertainty are reported for 10 \mmbμF, 100 \mmbμF, and 1 mF at frequencies of 100 Hz, 120 Hz and 1 kHz.