Measurement of Small Inductance

Abstract

THE method of suspending a loop of wire in a uniform alternating magnetic field, as used by Fleming and Elihu Thomson for the construction of A.C. galvanometers, can be applied with advantage to determine the self-inductance of loops in absolute measure, and it would seem that we can go considerably lower in this way than can conveniently be done otherwise. Low-frequency measurements are inaccurate, but with a triode at wireless frequencies I have measured inductances from 20 cm. to 50,000 cm. with an average error of 1½ per cent, without special precautions to obtain sensitiveness. The details of the experiment will appear shortly in the Philosophical Magazine.