On-line ultrasonic density sensor for process control of liquids and slurries

An on-line ultrasonic density sensor is described in which six transducers are mounted upon a plastic wedge, the base of the wedge being in contact wi th a liquid or slurry. Ultrasonic beams striking the base at several angles are reflected. The amount of reflection at the plastic-liquid interface de pends upon the density of the liquid rho, the speed of sound c in the liqui d, and wedge parameters. By determining the reflection coefficient at two a ngles, rho and c can be determined. The sensor can be mounted in a pipeline configuration or submerged for tank applications. (C) 1999 Elsevier Scienc e B.V. All rights reserved.