These polished polyacrylate blocks are used to investigate multiple echoes and measure frequency-dependent attenuation.

A 4 MHz transducer (U10017) is especially suitable for such measurements. An echo pattern comprising at least 3 echoes is recorded, and the spectra of the individual echoes analyzed. The result of the analysis is a shift in the average frequency toward lower frequencies, due to a stronger attenuation of the signal's high-frequency components.

Dimensions: 80x40x10 mm³