Eddy-current testing

Eddy-current testing uses electromagnetic induction to detect flaws in conductive materials. There are several limitations, among them: only conductive materials can be tested, the surface of the material must be accessible, the finish of the material may cause bad readings, the depth of penetration into the material is limited, and flaws that lie parallel to the probe may be undetectable.

Additional recommended knowledge

Essential Laboratory Skills Guide

Weighing the right way

How to quickly check pipettes?

However, eddy-current testing can detect very small cracks in or near the surface of the material, the surfaces need minimal preparation, and physically complex geometries can be investigated. It is also useful for making electrical conductivity and coating thickness measurements.

The testing devices are portable, provide immediate feedback, and do not need to contact the item in question. Recently tomographic notion of ECT has been explored see for example:

M. Soleimani, W. R.B Lionheart, A. J. Peyton, and X. Ma, S. Higson, A 3D inverse finite element method applied to the experimental eddy current imaging data, IEEE Trans Magnetics Vol. 42, No. 5, pp. 1560-1567, May 2006.

See also

• Eddy current
• Nondestructive testing
• An introduction to eddy current testing from the NDE/NDT resource center
• Database of NDT and Eddy Current Testing
• Eddy Current Non-Destructive Testing - B.P.C. Rao
• Intro to Eddy Current Testing by Joseph M. Buckley (pdf, 429 kB)
• EddyCation - the Eddy Current System for Education
• EC testing worldwide