Time-domain measurement of velocities and attenuation with low frequency acoustic microscope

A low frequency acoustic microscope which is operated in 10-50 MHz has been developed for precise measurement of leaky surface wave velocities and attenuation of engineering materials. The PVDF transducers are combined with a digital signal acquisition system in time-domain. Various digital signal processing are applied for the digitized waveforms, from which leaky wave velocity dispersion, attenuation are extracted. The system has been applied for measurement of the Young modulus of coating film, mass density of surface and attenuation of the leaky Rayleigh wave.