抄録
The electromagnetic acoustic transducer(EMAT) for Lamb wave, which consists of a meander coil with a distance of 2.5mm between two channels and has a symmetrical structure in the vertical direction for both surface sides of a thin steel sheet, has been researched as a flaw detector of thin steel sheets. This EMAT can generate some Lamb waves with variable wavelengths and multiple modes, and can separately generate symmetrical or anti-symmetrical mode Lamb waves.