Primary Realization of Inductance and Capacitance Scales With a Fully Digital Bridge

Abstract

This paper describes an automated electronic fully-digital bridge for the comparison of four-terminal-pair impedance standards in the audio frequency range. The bridge relative accuracy, which is on the order of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-6</sup> , makes it suitable as a reference bridge for the realization of primary scales of inductance and capacitance in metrology institutes and calibration laboratories. The performances of this bridge were validated by comparing the results of the calibrations of inductance and capacitance standards with those obtained from an existing analog reference system based on the three-voltage method. The paper also reports the results of this validation.