Fuji Electric Co., Ltd.

Masaru Kohno

Yukio Nakagawa

Kiyoshi Saito

Kazuteru Shinkai

Takeo Kada

Akira Kikuchi

Norimasa Tamaoki

Yukia Nakagawa

Gunzi Okawara

Akio Hagiya

An ultrasonic metering device having two ultrasonic transducers, each having an ultrasonic conversion element and a wedge for holding the conversion element, mounted on a pair of mounting members which are adapted to be mounted on a pipe in which a fluid to be measured flows. The mounting members clamp the pipe with first end portions of the mounting members being hingedly coupled to each other. Tightening means is provided for coupling opposite free end portions of the mounting members which have clamped the pipe to thereby fixedly secure the mounting members to the pipe.

Ultrasonic metering device

An ultrasonic measuring device for measuring the fluid flow of a high temperature fluid in a conduit. Ultrasonic transducers are mounted on first and second frames which have end portions hingedly coupled to one another. A tightening device at the other ends of the frames are used to secure the frames around the conduit carrying the fluid to be measured. Lead wires extend through hollow pipes between the ultrasonic transducers and connecting terminals at the outward ends thereof. Heat radiating fins may be provided at the outward ends of the pipes. With this construction, the outward ends of the pipes are at room temperature so that ordinary coaxial cables may be joined to the connecting terminals.

Ultrasonic measuring device

By detecting the instant of a selected zero-crossing of a received ultrasonic signal rather than relying on the instant the amplitude of that received signal exceeds a predetermined reference amplitude in excess of zero, a transit-time measuring instrument can be realized which is free from the measurement errors normally arising from acoustic signal attenuation in the medium through which it passes.

Ultrasonic measuring instrument

An ultrasonic measuring apparatus of the type having a pair of transducers disposed oppositely on a pipe through which a fluid to be measured flows and which are so controlled alternately as to convert an input electrical signal to an acoustic signal and to convert a received acoustic signal to a received electrical signal. The apparatus includes a time difference detecting means for receiving an output signal from a delay means and the received electrical signal for detecting a time difference between a delayed counting time obtained from the delay means and a propagating time required for an ultrasonic wave to propagate through the fluid to be measured. Comparing means are provided for comparing a voltage signal corresponding to the time difference with first and second set voltages and monitoring means receiving the comparison result from the comparing means for judging whether the fluid flow is propagated in the pipe in a normal condition or in an abnormal condition. The present invention ensures a quick detection of abnormal propagation of the ultrasonic wave in the pipe and obtains a correct measurement values without misjudgement.

Ultrasonic measuring apparatus

In an ultrasonic fluid flow rate measuring apparatus of the type having a pair of electro-acoustical transducers disposed in respective up-stream and down-stream positions relative a fluid flow and the flow rate is obtained from the difference between the oscillation frequencies of first and second oscillation circuits, the present invention includes an abnormality monitoring circuit responsive to a signal H corresponding to the output of the receiving transducer for providing an output signal W when the signal H exceeds an abnormality monitoring voltage E.sub.1, a trigger circuit for providing an output signal Z to a time difference detection circuit when the signal H exceeds a set voltage E.sub.3 and for providing in response to a signal F an output signal Z to the time difference detection circuit when the signal H exceeds a set voltage E.sub.30, and a mistrigger detection circuit for providing the output signal F when the output signal W is present and when a signal R from the time difference circuit exceeds a set voltage E.sub.61. The present invention further includes a delay compensation circuit for delaying by a predetermined period of time the providing of an output signal from a counter to a delay element, the predetermined period of time being set in accordance with the output signal F of the mistrigger detection circuit.

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Kawasaki, Japan

Masaru Kohno