Abstract
The nondestructive evaluations of structural materials such as SUS304, have been investigated by using a three-fold coils (6mm(L) x 2mm (D) typ.) composed of a pair of pick-up coils and an exciter coil. The three-fold probing coil shows an advantage of the high sensitivity for the material constant deviations from the some standard specimens. The probe coil is scanned over a specimen area to obtain 3-D map of material constants by analyzing the frequency dispersions of the eddy currents in a range between lkHz-300kHz.
