A method of using ultrasonic reflectance to characterize physical properties
of
fluids, particularly food solutions. In general, the method comprises the steps
of: (a) generating longitudinal ultrasonic waves, (b) coupling the transducer to
the fluid being investigated, (c) detecting the reflected longitudinal waves, and
(d) determining the physical property of interest by correlating certain characteristics
of the reflected ultrasonic waves with the physical property being measured. A
particular aspect of the invention is a self-calibrating ultrasonic device useful
as a solids concentration sensor and/or a dissolution/precipitation sensor. Self
calibration is accomplished via a twin delay line. The invention is particularly
useful as an on-line sensor in the processing of food solutions such as milk, ketchup,
syrup, chocolate and other confectionary.
