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

The paper describes a miniaturized device that records changes in voltage ampli tude 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 condi tion of the tested material. Registration of two parameters with different sensitivity for selected factors allows for a more accurate analysis of the condition of the tested material. The miniaturized device can works in manual measurement mode or in auto - matic mode, it can be used in defectoscopy, structure and thickness measurements.