Ultrasonic flow measurement of fluids such as natural gas, has acoustic transceivers that direct divergent beams of sound waves to sections of the pipe shaped to form parabolic reflectors

摘要

At ends of a measurement pipe (1) are located acoustic transducers acting as transceivers. The first (2) beams a divergent beam (4) of sound waves to a section (8) of the pipe shaped to form a parabolic reflector. This directs a parallel beam (9) to a second parabolic reflector (10) which directs a convergent beam (11) to the second transducer (3). Over the resultant sound path all the individual sound waves (5-7) have the same length so that the presence of turbulence in the pipe is indicated by time delays and frequency shifts between the individual waves.