Magnetometer Based on the Hall Effect

This paper describes a magnetometer for the determination of the saturation magnetization of magnetic materials. Unlike conventional magnetometers, the instrument described does not require well-defined movements of the sample and pickup coil relative to each other because the dipole field of the magnetized sample is converted into a dc electrical signal by means of a sensitive Hall probe. The instrument is simple in design, easy to construct, and relatively inexpensive. Test samples are prepared by pressing the magnetic powder into a brass cartridge to a constant volume. This technique yields samples of uniform and reproducible dimensions. Calibration of the instrument is made with a nickel sample of known magnetization. Magnetic moments of 20 gauss cm3 have been measured with an accuracy of 1%.