Surface and sub-surface discontinuities in conductive materials can be detected by means of this method. It is also possible to measure coating thickness and thickness of thin sheets. The interaction/variation of Eddy currents, which a probe induces, with the discontinuities is examined.

A magnetic field is developed around a copper coil that is excited with alternating current. This magnetic field generates induction currents (eddy currents) in conductive materials. Eddy currents generate their own magnetic fields, also called secondary magnetic fields. Discontinuities in conductive materials disturb Eddy current and the secondary magnetic fields; so, a test coil in the probe reacts. Discontinuities are detected by measuring and evaluating these reactions.

Standards:

• TS EN ISO 15548-X: Non-destructive testing – Equipment for eddy current examination.
• TS EN ISO 15549: Non-destructive testing – Eddy current testing – General principles.
• TS EN ISO 17643: Non-destructive testing of welds – Eddy current examination of welds by complex plane analysis.
• TS EN 1971-X: Copper and copper alloys – Eddy current test for measuring defects on seamless round copper and copper alloy tubes.