This document gives guidelines for ultrasonic attenuation spectroscopy methods for determining the size distributions of one or more material phases dispersed in a liquid at high concentrations, where the ultrasonic attenuation spectrum is not a linear function of the particle volume fraction. In this regime, particle-particle interactions are not negligible.
This document is applicable to colloids, dispersions, slurries, and emulsions. The typical particle size for such analysis ranges from 10nm to 3mm, although particles outside this range have also been successfully measured. Measurements can be made for concentrations of the dispersed phase ranging from about 5% by volume to over 50% by volume, depending on the density contrast between the continuous and the dispersed phases, the particle size, and the frequency range[ 9 ][ 10 ]. These ultrasonic methods can be used to monitor dynamic changes in the size distribution, including agglomeration or flocculation.