Principle of eddy current nondestructive testing

1. Eddy current flaw detection is a nondestructive flaw detection technology which uses alternating current electromagnetic coil to induce eddy current on the surface of metal components. It is suitable for defect detection of conductive materials, including ferromagnetic and non-ferromagnetic metal parts. Because eddy current flaw detection does not need close contact between the coil and the component, nor does it need to fill coupling agent between the coil and the component, it is easy to realize detection automation.

2. The principle is that the exciting coil is used to generate eddy current in the conductive element, and the change of eddy current is measured with the help of the detecting coil, so as to obtain the information of component defects;

3. In eddy current testing, in order to adapt to different flaw detection purposes, according to the relationship between the detection coil and the inspected component, the detection coil can be divided into three categories: penetrating coil, inner coil and embedded coil.