Orthogonal fluxgate magnetometer utilizing bias switching for stable operation

Abstract

A new mode of operation is described for an orthogonal fluxgate built with a thin magnetic wire. In this mode, a dc bias is added to the ac excitation and the fundamental component of the induced voltage is a measure of the axially applied magnetic field. A bias switching method for reducing offset and drift is proposed for the orthogonal fluxgate operating in the new mode. Preliminary results on the resolution and the stability are presented.