This work describes the development and tests of a new ultrasonic spectrometer for liquids based on the use of commercial cuvettes for sample handling. The spectrometer operates in the frequency range from 20 to 80 MHz and gathers some important characteristics, which are its high thermal stability (better than 0.01°C), by the use of Peltier cells, and practical sample handling with small volume (≤3 ml) samples placed inside cuvettes which can be easily removed from the spectrometer, cleaned/sterilized, or simply discarded. Throughtransmission operation is used to measure propagation velocity and attenuation coefficient, and the spectrometer was tested with mixtures of water and NaCl, which have attenuations smaller than that of distilled water, and higher attenuation samples of silicone and castor oil. Backscattering studies of polystyrene particles of 10-and 15-μm diameters were also conducted, showing the versatility of the instrument. Index Terms-Attenuation, backscattering.
Funding
This work was supported in part by São Paulo Research Foundation (FAPESP) under Grant 2014/09034-8 and Grant 2014/09038-3, in part by the National Council for Scientific and Technological Development (CNPq), in part by the Instituto de Salud Carlos III under Project PI16/00738, and in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—under Grant 001
