REDISTRIBUTING MAGNETIC CHARGE IN BIAS ELEMENT FOR MAGNETOMECHANICAL EAS MARKER

摘要

A bias element (10) for use in a magnetomechanical EAS marker is magnetized to saturation (14). Then the magnetic charge in the bias element is redistribut ed (16) by applying to the bias element a magnetic field having an AC ringdown characteristic. The redistribution of magnetic charge improves the stability of the bias element, so that the marker incorporating the bias element is le ss likely to have its resonant frequency shifted by exposure to a stray magneti c field.