The amplitude-frequency measurement in non-destructive testing using the eddy current method

Abstract

The paper describes a miniaturized device that records changes in voltage amplitude and signal frequency. After applying the measuring probe to the surface of the tested material, the voltage and frequency amplitude changes. In a place free from defects and nonconformities values of voltage amplitude and frequency are taken as reference values, with which the results obtained during further tests are compared. A clear change in the value of any of the parameters indicates a change in the condition of the tested material. Registration of two parameters with different sensitivityfor selected factors allows for a more accurate analysis of the condition of the testedmaterial. The miniaturized device can works in manual measurement mode or in auto-matic mode, it can be used in defectoscopy, structure and thickness measurements.