Eddy current (EC) is a method using magnetic fields for detecting and measuring metallic objects. Transmitting coils in a probe are charged by...

Eddy current (EC) is a method using magnetic fields for detecting and measuring metallic objects. Transmitting coils in a probe are charged by current and thus generate a primary magnetic field. On the surface of metallic objects within the magnetic field, eddy currents are induced, which produce a secondary magnetic field in the opposite direction. The resulting change of voltage in the receiving coils can be utilized for measurement.

Eddy current method is used in NDT for detecting and measuring steel rebars within the concrete.