Eddy Current Testing

Eddy current testing is based on the physical phenomenon of electromagnetic induction. In an eddy current probe, an alternating current flows through a wire coil and generates an oscillating magnetic field. If the probe and its magnetic field are brought close to a conductive material, such as a metal test piece, a circular flow of electrons known as an eddy current begin to move through the metal like swirling water in a stream. That eddy current flowing through the metal in turn generates its own magnetic field, which interacts with the coil and its field through mutual inductance.