Ultrasonic vortex flowmeter having clamp-on housing

摘要

An improved ultrasonic vortex fluid flowmeter (10) includes a housing (12) having a slip-on yoke (16) which removably mates with a bluff body conduit connector (18) permanently installed in a fluid conduit to be monitored. An ultrasonic transmitter (40) and receiver (42) are respectively positioned within the legs of the yoke so as pass an ultrasonic wave through vortices (43) shed by the fluid as it flows by the bluff body (28). The slip-on yoke eliminates both the need to shut down fluid flow during meter servicing, and the potential for external contaminants entering the fluid. The flowmeter further utilizes a simple phase detector formed from an Exclusive Or gate (44) in combination with an optimal phase range detecting means (108). The optimal phase range detecting means triggers a 90 degree phase shift whenever the phase difference between the transmitted wave and the received wave approaches 0 or 180 degrees.