Abstract: Apparatus employing ultrasonic pulse production at a transmit transducer at a known frequency is received at a receive transducer for sampling a liquid slurry of known composition, but unknown ratio, makeup of liquid, gas and fine, suspended particles. The transmission time is converted to digital form and an adjustable velocity-density slope factor is applied from empirical data to result in a readout voltage that directly relates to the density of the liquid slurry.