Eddy current testing (EDT) is a kind of testing method to detect the surface and near surface defects of conductive prefabricated components based on the basic principle of magnetic effect of electric current. One of the methods of high quality inspection in industrial production. When an in-line eddy current detector coil is fed into an alternating current, the current based on the current does not change under certain standards. If the coil is close to the tested product workpiece, like a ship in the water, the product workpiece will be magnetic induction eddy current, by eddy current harm, coil current flow will produce changes. Because the size of the vortex varies with the presence or absence of defects in the product, the size of the coil current transition can indicate the presence or absence of defects.
Advantages of eddy current flaw detection
1, eddy current testing coil does not need to be directly in contact with the measured object.
2, the detection results can be output by electronic signal immediately, so it can be used for automatic detection technology.
3. Because of the implementation of non-contact detection, the detection speed is fast.
4, a wide range of applications, in addition to can be used to detect defects, can also be used to detect material change, eddy current flaw detector calibration device appearance and specification change, etc..
Limitations of eddy current testing