Automatic setup for inductance measurement at IEN

A measurement system that compares an unknown inductor to a standard AC resistor, based on the three-voltmeter method, is presented. The main features of the system are: a two-phase generator for energizing the standards, the four-terminal pair definition of both standards with automatic techniques, a switching unit to employ a single voltmeter, optical links for the distribution of frequency references. Measurements at metrological level have been performed at 1 kHz with inductors in the range 10 mH-1 H.