Sensitivity of inductances to magnetic fields

This paper presents a method used to measure the magnetic sensitivity of inductances. The measurement is performed by using an LC oscillator whose frequency is determined by the inductance to be measured. Because the records are often perturbed by noises and drift the data are processed so as to enhance the signal-to-noise ratio and to suppress the drift. A wide range of inductances have been measured. The results show that, according to their technology, for a magnetic field of 10 Gauss amplitude, the sensitivity may go from 0.1 ppm to 1400 ppm with sometimes a large spread of values in a given batch.