Patent ID: 7010979

Claim:
A particle size distribution monitor, comprising: (a) a transducer adapted to be a source of ultrasonic energy and positioned in contact with a suspension containing a percent by volume of particles in a liquid, the transducer transmitting ultrasonic energy through the suspension wherein the energy comprises a wideband pulse containing a range of frequency components; (b) a transducer adapted to be receive of ultrasonic energy and positioned in contact with said suspension to receive said wideband range of ultrasonic energy which has passed through the suspension; (c) first means adapted to accept a signal from said receiver and make an instantaneous determination of the attenuation of the wideband ultrasonic energy in passing through the suspension comprising (i) an A/D digitizer for said signal, (ii) an FFT analyzer for the digitized signal, (iii) means to obtain the magnitude of the FFT data representing the measured attenuation, and (iv) means of controlling an additional attenuation of said signal from the receiver before it is processed by the A/D digitizer; and (d) second means comprising means to determine an estimated PSD and means to compare the estimated PSD with the measured attenuation and determine the goodness of the fit.