Subminiature eddy current transducers for studying aluminium-dielectric and steel-dielectric junctions

摘要

Based on a eddy current transducer (ECT), a probe has been designed to research metal-dielectric structures (MDS). A scheme that uses a computer as a generator and receiver of signals from windings is proposed. 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. A hardware-software complex was built to perform experimental studies of steel at the interface boundary. Test results are reported for a specimen with continuous and discrete measurements taken at different frequencies. The curve of introduced voltage amplitude as a function of sensor location was constructed to study in detail the introduced voltage drop at the ferromagnetic-dielectric interface.