Electromagnetic Testing

This process subjects material to an electromagnetic field. Eddy currents are induced in the metal and magnetic fields are created as a result. Surface seams, cracks, slivers or laps affect the currents and fields which, when read by a sensing device and compared against a standard, indicate the type, size and location of the imperfection. Factors such as surface smoothness, grade, prior thermal treatment and cold working can influence the accuracy. Also referred to as “eddy current” testing, it is not the same as a magnetic particle test.