Simple Inductance Measurement Method Using a Commercial LCR Meter

Abstract

A simple measurement method, which determines inductance from the capacitance standards, is presented. This method is cost effective because no special instrument other than a commercially available LCR meter is used. The measurement principle is the compensation method using the LC series circuit. At the frequency near its resonating condition, the reactance of the inductor is offset by that of the capacitor. The reactance of the capacitor was precisely calibrated beforehand, and the LCR meter measures the reactance value of the residual difference much smaller than the total reactance of the inductor itself. This means that the accuracy of LCR meter affects the measurement uncertainty of inductance less than the uncertainty of direct deflection measurement of inductance. Two 10 mH standard inductors and a 100 mH standard inductor were measured at 1592 Hz (angular frequency of ω = 104rad/s). The relative combined standard uncertainties of measurement were estimated to be 9.2 parts per million (ppm), 9.8 ppm and 12.0 ppm, respectively. These values are small enough for the industrial use. © 2005, The Institute of Electrical Engineers of Japan. All rights reserved.