Eddy Current Testing is an electromagnetic technique. When an energized coil is brought to the surface of a metal component, eddy current are induced into the specimen. These currents set up a magnetic field that tends to oppose the original magnetic field. The impedance of the coil in close proximity to the specimen. When the eddy-current in the specimen are distorted by the presence of the flaws or material variations, the impedance in the coil is altered. This change is measured and displayed in a manner that indicates the type of flaw or material condition. Its application range from crack detection, to the rapid sorting of small components for flaws, size variations or material variation. E.g. Heat exchanger, Boiler, Coolers, Condenser, Other specialized functions and so on.