A surface eddy current transducer for metal loss detection

The paper reports the results of an experimental study of the work of a surface eddy current transducer in terms of detecting and testing metal loss under one-sided access conditions. The transducer consists of an exciting coil and a microchip Hall-effect transducer placed in it. The phase shift of the voltage from the Hall probe output relative to the current in the exciting coil, measured by a digital phase meter, is used as an informative parameter. The experiments were carried out on a package of duralumin plates. It is shown that, when the thickness of the duralumin test object is 12.5 mm, a fairly linear transformation of metal loss from 0 to 50 % at a frequency of 640 Hz is possible. The results can be useful in the development of devices for detecting metal corrosion losses in non-ferromagnetic objects with a thickness of tens of millimeters under one-sided access conditions.