NASA's Langley Research Center has developed a magnetometer that takes advantage of the unique variable permeability properties of Metglas 2714A magnetic material. By measuring directly the inductive reactance of a simple right circular cylindrical search coil through the application of current from a high-output-impedance current source driven with a 10-kHz sinusoidal voltage, a magnetic field sensor having a 700-Hz bandwidth, good linearity, and excellent noise performance with sensitivity at least as good as the 0.1 nTesla range was produced.
The magnetometer consists of a circular cylindrical coil with a magnetic core. It is inherently stable with variations in environmental conditions such as temperature. The simplicity of construction is an advantage over the flux gate design. Circuit stability is achieved through the use of a crystal oscillator for frequency stability and matched resistor networks for amplitude stability in the voltage readout.
This technology can be used in aerospace applications, weather monitoring, EMP detection, magnetosphere research, monitoring Earth's magnetic field, solar system study, and tracking solar flare activity.