Matsushita Electric Industrial Co., Ltd.

Naoko Azuma

Masahiko Hashimoto

Akihisa Adachi

Kenzo Ohji

Atsushi Watanabe

Tooru Ninomiya

The present invention provides an ultrasonic transducer having uniform characteristics. Because the characteristics of a pair of ultrasonic transducer are equalized with each other, measuring accuracy of an ultrasonic flowmeter can be improved. Electrical connection from an electrode surface of a piezoelectric body to an external electrode is achieved not by soldering but by an electroconductive elastic body . As a result, variations of the frequency characteristics due to thermal load on the piezoelectric body can be reduced, and this makes it possible to obtain an ultrasonic transducer with uniform characteristics, and measuring accuracy of an ultrasonic flowmeter using a pair of the ultrasonic transducer can be improved.

Ultrasonic transducer and ultrasonic flowmeter

An ultrasonic flowmeter includes a flow passage and an ultrasonic transducer for measuring the flow rate in the flow passage wherein the ultrasonic transducer is equipped with 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 electrode direction 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 thickness 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.

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Kawasaki, Japan

Naoko Azuma