Ultrasonic method of monitoring particle size distribution of a medium

A method of determining a particle size distribution of particles within a sample medium, comprising the steps of:

• providing an ultrasonic transmitter and receiver separated by a fixed path length for transmitting and receiving ultrasonic waves;
• employing the ultrasonic transmitter and receiver to measure an ultrasonic attenuation spectrum of said sample medium;
• calculating, with a computer processor, a simulated attenuation spectrum obtained from a model comprising the calculation of a scattering cross-section;
• calculating, with the computer processor, a frequency-dependent weight factor, said weight factor obtained by determining, at each frequency interval within said measured attenuation spectrum, a value related to a ratio of a transmitted ultrasonic power within said frequency interval to the total transmitted ultrasonic power;
• employing the computer processor to multiple said measured attenuation spectrum and said calculated simulated attenuation spectrum by said weight factor;
• employing the computer processor to vary parameters of a model to minimize an error between said multiplied simulated attenuation spectrum and said multiplied measured attenuation spectrum, thereby obtaining optimized parameters;
• and
• calculating, with the computer processor, said particle size distribution from said optimized parameters.