Spherical acoustic resonators for temperature and thermophysical property measurements
Michael R. Moldover, Martin Greenspan, Meyer Waxman
A theoretical and experimental study is reported of the advantages and limitations of using the acoustic radial resonances in a spherical cavity to obtain thermophysical property data in dilute gases. The velocity of sound in dilute gases (0.1-0.5 MPA) is now measured with an accuracy of 0.02% and a precision of 0.001%, and a significant increase in accuracy is anticipated. The measurements are at sufficiently low frequencies (3-15 kHz) to be of value in determining thermophysical properties in many polyatomic gases.