Eddy Current Testing Basics and Innovation

Abstract

Eddy current testing is considered a theoretically challenging technique. Out of all the different nondestructive testing (NDT) methods, the electromagnetic testing (ET) method (of which eddy current testing is a technique) is probably the most difficult for understanding theory. This is perhaps why the last Materials Evaluation Back to Basics paper on eddy current testing is from 2006, which is a long time ago given the amount of innovation in the technique that has taken place since then (Hansen and Peoples 2006). In this paper we will show what has changed due to recent innovations. We first will present the physics, and then explain how modern equipment assists the user in distinguishing between different physical phenomena. Although this paper is on conventional eddy current testing, we will also mention some other ET techniques along with their advantages and disadvantages.