Design and performance evaluation of the NIST digital impedance bridge

An impedance bridge that compares two-terminal standard inductors to characterized resistors is described. A dual-channel digitally synthesized source and sampling digital multimeter are used to generate and measure relevant bridge signals. A linear interpolation algorithm is used to autocalibrate the bridge to a 1 nF air-dielectric capacitor. An intercomparison of the new bridge with existing measurement standards in the low audio frequency range for inductors 1 mH to 10 H is reported.<
>