Measurements of Extremely Small Inductance Values: Offset elimination technique for small inductance measurements using two-wire connection

Abstract

Measurement of small inductors is the trickiest compared to other component testing using typical LCR-meters providing test frequency of 100 kHz or lower. Inductance of 1 nH at 100 kHz only produces 6 mOhm impedance that is comparable to a contact resistance of the probes. Even at 1 MHz the impedance would only be 60 mOhms. We demonstrate a simple method of extraction of the two-wire probe parasitic inductance using HP4284A LCR-meter and HP16034E test fixture. The method effectively allows to measure sub nH inductors.