Ultrasonic sensor for the characterization of colloidal slurries

A bulk wave acoustic sensor capable of measuring PSD (particle size distribution) for both low- and high-concentration slurries has been designed, fabricated, and tested. The principle of operation of the sensor is based on the measurement of the variation of the attenuation of the acoustic wave in the slurry as a function of frequency. The attenuation data are then incorporated into a theoretical model to predict the PSD of TiO/sub 2/ particles in the slurry. The sensor is capable of detecting the PSD of the TiO/sub 2/ particles with sizes ranging from 0.1 to 10 mu m in high-concentration slurries, up to 75 weight percent. A potential application of the sensor is in process control in the manufacture of pigments or slurries for use in paints and paper coatings. >