The transformer bridge and magnetic susceptibility measurement

Abstract

The measurement of the magnetic susceptibility of rock specimens, at low fields, commonly employs instruments which measure the change in an inductive circuit when a sample is introduced into the magnetic flux path of the inductor. In many cases this takes the form of a transformer bridge. Some time ago the CSIRO Division of Mineral Physics recognised a need for such a bridge for use in research. Known existing designs appeared inadequate, and it was considered expedient to develop a new instrument with significantly improved performance.