抄録
Lamb waves are normally utilized for inspecting thin metal sheets. Recently, an electromagnetic acoustic transducer (EMAT) has been developed and is beginning to be used as a Lamb wave detector. The EMAT offers the advantage of inspection without using a couplant. The EMAT generates Lamb waves with fixed wavelengths determined by the interval between the meander lines in the sensor coil that constitutes the EMAT. We have studied an EMAT consisting of a meander line coil with intervals from 1mm to 4mm and having a paired structure symmetrically embraced with a thin steel sheet on opposite sides.
