Accession Number : AD0487026

Title :   MEASUREMENT OF ACOUSTICAL IMPEDANCES OF FLUIDS BY ANALYSIS OF TRANSIENT ACOUSTIC WAVESHAPES USING AN ACOUSTICAL WAVEGUIDE WITH PIEZOELECTRIC TRANSDUCERS.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Sheehan, James Edward

Report Date : MAY 1966

Pagination or Media Count : 66

Abstract : A method has been developed for measuring the acoustic impedance of fluids in a fluid-filled waveguide terminated at each end by piezoelectric crystals. Output voltage waveforms were computed for the general case of an arbitrary driving voltage. Analysis of these output waveforms, when the driving voltage was an impulse function, indicated significant changes in the voltage envelopes as the acoustic impedance of the fluid within the waveguide was varied. The time of the first and second phase changes in the second received echo were plotted as a function of fluid impedance. Test fluids were analyzed with an impedance range of from 0.66 times 10 to the 6th power rayls to 19.7 times 10 to the 6th power rayls. The experimental results using the time of the second axis crossing or phase change as the test criterion, indicated that the acoustic impedance can be measured.

Descriptors :   *FLUIDS), (*ACOUSTIC IMPEDANCE, WAVEGUIDES, PIEZOELECTRIC TRANSDUCERS, MEASUREMENT, VOLTAGE, WATER, ACETONES.

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE