Gap-modified magnetic bridge device for fringing flux analysis

摘要

Various devices are constructed with gap-modified magnetic bridge circuits. In a magnetic bridge device for evaluation of samples, a magnetic bridge circuit has at least four arms, a driving leg and a sensing leg, one of the arms being utilized for evaluating a sample, pole pieces of a sample-evaluating arm having end faces defining between them a sample-evaluating gap. An electrically conductive gap insert produces an enhanced fringing flux exteriorly of it. The sample is placed in juxtaposition to the sample-evaluating gap for affecting the fringing flux. A driving circuit for the driving leg provides a time-varying flux path within the four arms of the bridge. A sensing device associated with the sensing leg senses changes in the sensing leg caused by changes in the fringing flux resulting from characteristics or movement of the sample. A specific single-side modification provides an accelerometer.