What is Eddy Current Testing?

Eddy Current Testing (ECT) is a non-destructive testing (NDT) method used to detect surface and near-surface flaws in conductive materials. It works by inducing eddy currents (circulating electric currents) in the test object using an alternating current-carrying coil. These eddy currents are affected by discontinuities or variations in the material's conductivity and permeability. Changes in the eddy currents are then detected by the same or a separate coil, providing information about the presence, size, and location of flaws, as well as material properties like thickness and conductivity. It is commonly used for crack detection, material sorting, and coating thickness measurement.