METHOD FOR DISTINGUISHING BETWEEN SEMI-SOFT AND SOFT MAGNETIC MATERIAL

摘要

A method for distinguishing between a semi-soft magnetic material, having a magnetic saturation field H>s< ranging from 100 A/m to 3000 A/m, and a soft magnetic material, having a magnetic saturation field H>s< ranging from 3 A/m to 100 A/m, comprises following steps: (a) emitting an electromagnetic drive signal of one or more particular frequencies to an article so that any present semi-soft magnetic material or soft magnetic material in the article go into saturation for both positive and negative magnetic fields; (b) detecting an electromagnetic detection signal (20) emanating from the article; (c) measuring time or relative phase delays (A, B) between one or more reference points of the drive signal and points at which positive and negative peaks of the detection signal occur; (e) comparing the measured time or relative phase delays with values which are typical for semi-soft magnetic or soft magnetic features in order to make a decision whether the material is soft magnetic or semi-soft magnetic.