Measurement of the intrinsic attenuation of longitudinal waves in anisotropic material from uncorrected raw data

Longitudinal wave attenuation measurements by means of a diffraction-insensitive large-aperture PVDF hydrophone

“…Neither a decomposition of the ultrasound fields into the Fourier space domain nor a computation of the transmission coefficients is required. It has been demonstrated that the measurement results obtained by means of both the MEM and CEM, respectively, are very similar [14] . However, it is apparent that the large number of observation points for mapping the entire ultrasound field by means of a needle-type hydrophone takes a considerable amount of time.…”

“…In cases where the examined material is anisotropic, it may even be necessary to scan several samples before the intrinsic attenuation can be estimated as a function of the propagation direction. In reference [14] for example, 18 samples were used and it took approximately 20 working days to measure the intrinsic longitudinal wave attenuation in reactor pressure vessel strip cladding in the frequency regime of about 2 MHz. Investigations above or below this regime may require the employment of a different emitting transducer and the entire process has to be repeated.…”