Method and apparatus for measuring acoustic wave velocity using impulse response

TLDR: In this article, the transit time of acoustic waves between a generator and a receiver positioned across a fluid chamber is determined by generating acoustic waves using a self-purging pneumatic sound generator, a transducer adjacent the outlet of the sound generator and positioned away from the sound generators outlet so that the acoustic waves received by the receiving transducers pass through a portion of the fluid.

Abstract: The transit time of acoustic waves between a generator and a receiver positioned across a fluid chamber is determined by generating acoustic waves using a self-purging pneumatic sound generator, a transducer adjacent the outlet of the sound generator, and a receiving transducer positioned away from the sound generator outlet so that the acoustic waves received by the receiving transducer pass through a portion of the fluid. The electrical signals generated by the transmitting transducer and the receiving transducer are processed to obtain the impulse response of these electrical signals, and the point of maximum value is determined. This point of maximum value corresponds to the arrival time of the acoustic waves at the receiving location. The transit time determination may be used to calculate the fluid temperature or other parameters. The pneumatic sound generator is driven by a compressed air source so that the generator is automatically purged of any contaminants in the process of generating the random acoustic noise.