Abstract
An ECT signal from a small reverse-side defect existing on a thick metallic plate is very small because of the long distance between the probe and the defect. To detect a minor reverse-side defect on a thick metallic plate, we therefore have to develop a new ECT probe with high sensitivity. We developed a new ECT probe with a gradio-magneto sensor, which consists of two MI elements and a CMOS electric drive circuit. The experimental results show that this new ECT probe using MI elements shows high sensitivity and stability.
