Subminiature eddy current transducers for studying metal-dielectric junctions

Abstract

Based on a transformer eddy current transducer (ECT), a probe has been designed to study metal-dielectric-metal structures. The structural diagram of the probe is given and the basic technical data are stated (the number of windings is 10–130 turns, and the value of the initial permeability of the core μmax = 500). The scheme that uses the computer as a generator and receiver of signals from windings is considered. The measurement procedure allowing one to detect defects in laminate composites with a high accuracy is described. The transducer was tested on the layered structure consisting of paper and aluminum layers with a thickness of 100 μm each in which the model defect was placed. The dependences of the ECT signal on the defect in this structure are given.