ULTRASONIC FLOWMETER AND ULTRASONIC GENERATOR/DETECTOR

摘要

An ultrasonic flowmeter includes a flow passage and an ultrasonic transducer for measuring the flow rate in the flow passage wherein the ultrasonic transducer comprises a piezoelectric material having electrodes on the opposed surfaces thereof, one of which is used as an ultrasonic wave transmitting/receiving surface and faces the flow passage. The lengths of the sides of the transmitting/receiving surface is so determined that the vibration in the direction vertical to the transmitting/receiving surface is the main mode, preferably that the ratio of the lengths of the sides of the transmission/reception surface to the thickness is not greater than 0.8. Consequently, because the flow meter uses the longitudinal vibration of the piezoelectric material as the main mode, the ultrasonic transducer has a high sensitivity, a high speed response and a small size and the ultrasonic flow meter has a high accuracy and is compact.