EXPERIMENTAL INVESTIGATION OF ACOUSTIC SIGNATURE V(Z) FROM THE HALF-FOCAL PLANE

Acoustic signature V(z) measurement produced by acoustic microscopes r equires first the adjusting of the echo corresponding to the focal pla ne. However, in some processing conditions, one can confound the echo coming from the focal plane with the one coming from the half-focal pl ane, the latter also being a damped periodical signal. We propose an a nalysis of the phenomenon observed on the acoustic signature obtained at the half-focal plane and we show that these signatures depend not o nly on the sample nature but also on the nature of the material consti tuting the transducer.