Broadband ultrasonic attenuation measurements using coded sweep excitations

An experimental method to measure ultrasound attenuation was developed in which the frequency spectrum (FS) of a system consisting of a transmit/receive pair of ultrasonic transducers was broadened from 1.79 MHz to 4.57 MHz. A nonlinear specially designed sweep was employed, which was coded based on the FS of the ultrasonic system. Both coded and linear sweeps were used with the attenuation measurements of a 0.90 glycerol to 0.10 water mixture. Experimental and theoretical results agree with each other to within 0.5 dB. With the proposed method, the frequency range of validated results was improved, since it was possible to enlarge the useful bandwidth of the ultrasonic system without substituting any of the devices from the experimental set up.