Development of a Vibrating-Coil Magnetometer

Abstract

The vibrating‐coil magnetometer measures the magnetization of a small sample of magnetic material placed in an external magnetizing field by converting the dipole field of the sample into an ac electrical signal. To allow space for temperature‐ or pressure‐generating apparatus around the sample, the measurement is made at distances up to 2 cm from the sample. The measurement is continuous and can be recorded on a chart as a function of time, temperature, crystallographic orientation, or magnetizing field. The present stable sensitivity is such as to provide one percent accuracy for a dipole moment of 8.56×10⁻⁴ amp‐m² (the saturation moment at room temperature of a nickel sphere 1.5 mm in diameter).