Eddy Current Testing

When a coil, energised with high frequency alternating current, is placed close to a conductive material it will

produce eddy currents in the material. These currents produce a magnetic field in the test specimen. A search coil, used in

conjunction with the energised coil, can be connected to an electronic recording device. Any defect in the material distorts the magnetic

field. This is indicated on the recording device. The magnitude of the distortion reflects the size of the defect. A suitable application is the

detection of surface or subsurface flaws in nonferrous metals of uniform section.