Eddy Current Testing Procedure as per ISO 17643 and Acceptance Criteriya
Eddy current testing is a modern NDT method and prime tool in controlling quality of components for Aerospace, heat exchanger tubes, oil & gas and structural applications at various stages of manufacturing and in-service inspections for surface and subsurface crack testing. This method can be used to find finest surface and subsurface flaws in any conductive material. Present Eddy current NDT method has applications in companies, real time non-contact thickness measurement to control process quality, Material sorting, mixing, Paint and nonconductive coating thickness measurements. Demand for testing is steeply rising due to increasing usage of nonferrous conducting materials for vast number of engineering applications.
Principle of Eddy Current testing
Specimen is brought into proximity to the alternating flux field of an eddy current coil, coil flux causes electrons in the specimen to circulate in a eddy-like pattern; hence the term “eddy currents.”Eddy current behavior depends on the properties of both the flux and the specimen itself. So eddy currents are circular alternating currents caused by a varying magnetic field.