Eddy current testing of weld zone using uniform eddy current probe

摘要

When conventional eddy current testing using a pancake probe is applied to maintenance inspection of a weld zone, it is difficult to detect flaws because of the noise generated by the liftoff change and the electromagnetic characteristic change of the weld zone. The authors have developed a new uniform eddy current probe that consists of a wide tangential exciting coil and differential detector coils to detect flaws at the weld zone. The uniform eddy current probe is much less influenced by variations of the probe lift-off and the electromagnetic characteristics of the test material than the conventional pancake probe. The authors have tried the eddy current testing of a weld zone using the uniform eddy current probe. The experimental results proved that the uniform eddy current probe has a higher signal-to-noise ratio than the conventional pancake probe when applied to detecting flaws.