Application of EMAT/EC dual probe to monitoring of wall thinning in high temperature environment

Abstract

Eddy current testing (ECT) and ultrasonic testing (UT) have been widely used for the non-destructive testing of metal structures. ECT has a high capability of sizing surface breaking cracks and UT is suitable for sizing sub-surface breaking cracks in thick-wall structures. Based on this background, the authors have proposed a novel dual probe with simple structure combining an electromagnetic acoustic transducer (EMAT) and Eddy current probe. The performance of the probe was verified at room temperature. However, the operating temperature of boiling-water nuclear reactors is 300 degrees C. In this paper, the above dual probe is applied to monitoring of piping wall thinning in a high temperature environment. For this purpose, the structure and components of the probe are discussed so that the present probe should withstand 300 degrees C. Finally, the basic performance of the probe at high temperatures is investigated through an experiment using an electric furnace.