Patent ID: 6065350
Filing Date: 2000-05-23
Classification: G01D,G01F

Abstract:
An ultrasonic measurement system for measuring flow of a fluid in a conduit, such system comprising:a transmitting transducer for generating a vertically polarized shear wave signal at a frequency .function. above cut off;a wedge coupling the transmitting transducer to the conduit, said transmitting transducer propagates said signal into the wedge, and said wedge formed of a material having a sound speed below about 1400 m/sec and being comparable to sound speed of a material of said conduit, said wedge is angled to launch said signal at a launch angle into said fluid;a receiving transducer spaced along the conduit from the transmitting transducer and coupled to the conduit to receive a lowest order acoustic wave signal after propagation through the fluid in the conduit and producing a received signal indicative thereof; anda processor in communication with the receiving transducer to determine a transit time interval from the received signal;wherein the wedge is configured such that the launch angle lies within an acceptance angle of said conduit effective to propagate the signal in said fluid axially along the conduit as the lowest order mode acoustic wave signal guided along the conduit as a strong signal without mode re-converting.