ULTRASONIC MEASUREMENT

摘要

PCT No. PCT/GB83/00226 Sec. 371 Date May 15, 1984 Sec. 102(e) Date May 15, 1984 PCT Filed Sep. 15, 1983 PCT Pub. No. WO84/01233 PCT Pub. Date Mar. 29, 1984.A parameter such as the depth (d) of a liquid (12) in a tank (10) is measured by use of an ultrasonic transducer (14) outside the tank (10). This is possible by choosing the ultrasonic frequency and the thickness of the tank wall such that a defined relationship is satisfied.