Which physical property is primarily utilized in eddy current testing?

Eddy current testing primarily utilizes electrical conductivity as its key physical property. In this method, an alternating current is passed through a coil, which creates a changing magnetic field. When this magnetic field interacts with a conductive material, it induces eddy currents within that material. The amount and behavior of these induced eddy currents depend significantly on the electrical conductivity of the material being tested.

Materials with higher electrical conductivity will generate stronger eddy currents, while those with lower conductivity will result in weaker currents. This variation in eddy current response can be analyzed to detect surface and near-surface defects, measure material thickness, and identify the material type. Such applications demonstrate how essential electrical conductivity is in effectively utilizing eddy current testing techniques.