Evaluation of an EMAT–EC dual probe in sizing extent of wall thinning

• An EMAT–EC dual probe purpose built for wall thinning evaluation is proposed.
• Sizing methods of wall thinning by EMAT and EC operating modes are investigated.
• Capability of EMAT and EC operating modes is quantitatively evaluated and mode complementarity of the dual probe is demonstrated.

An electromagnetic acoustic transducer (EMAT)–eddy current (EC) dual probe is developed to assess wall thinning. With a view to developing compatible EMAT and EC operating modes, probe’s capability to size width and depth of wall thinning is quantitatively evaluated. Experiments carried out on austenitic stainless steel plates with various groove sizes show that the EMAT mode of the dual probe functions best when thinning is shallow but wide, whereas the EC mode functions best when thinning is deep but narrow. Mode complementarity indicates that this dual probe offers greater reliability in wall thinning monitoring.