Eddy Current Inspection (ECI) is an advanced electromagnetic nondestructive testing (NDT) method used to detect surface and near-surface defects in conductive materials such as aluminum, copper, steels, heat exchanger tubes, aircraft components, welds, fastener holes, and tubing systems
Eddy Current Inspection (ECI) is an advanced electromagnetic nondestructive testing (NDT) method used to detect surface and near-surface defects in conductive materials such as aluminum, copper, steels, heat exchanger tubes, aircraft components, welds, fastener holes, and tubing systems.
It works on the principle of electromagnetic induction. When an alternating current is passed through a probe coil, it generates a changing magnetic field, which in turn induces circulating “eddy” currents in the test material. Any change—such as cracks, corrosion, material thinning, hardness variations, or conductivity differences—disturbs these eddy currents. This disturbance changes the probe coil’s impedance, which is displayed on the eddy current instrument as a signal indication.