With the eddy current test facial and near-surface defects and material inhomogeneities can be detected. The eddy current test can also be used for detection of material properties such as residual stresses, hardness, strength etc.
The material to be tested has to be electrically conductive. The effect that material errors and inhomogeneities have an other electrical and magnetic conductivity than the material itself, is exploited.
Engineer standards: DIN EN ISO 15549 (ET general)