Multi-frequency eddy current control of structural steel sheets

The results of the study of the effect on the results of eddy current testing of the thickness of structural steel sheets of such a parameter as the force of pressing the eddy current sensor to the surface of the object of control are presented. To isolate the controlled parameter, experimental values of the introduced resistances of an eddy current converter obtained using multi-frequency measurements were used. The dependences of these resistances for the overhead eddy current transducer sensor on the clamping force and thickness of the steel sheet are revealed. A method for processing the results of eddy current measurements is proposed, which ensures the elimination of interfering parameters and reliable isolation of the controlled parameter.