Accurate Measurements of Thermodynamic and Transport Properties of Industrial Gases with Acoustic Resonators.

Published

September 2, 2001

Author(s)

Keith A. Gillis, John J. Hurly, Michael R. Moldover

Abstract

Acoustic resonators have been developed at NIST as tools to measure the thermodynamic and transport properties of gases. High Q cylindrical acoustic resonators are routinely used to measure the speed of sound in gases with uncertainties of 0.01% or less. Model intermolecular potentials are fitted to the acoustic data to obtain virial coefficients, gas densities (rho), and heat capacities Cp with uncertainties of 0.1% as well as estimates of the viscosity (eta) and thermal conductivity (lamda) with uncertainties of less that 10%. The viscosity is measured directly with uncertainties of less than 1% using the Greenspan acoustic viscometer, a novel acoustic resonator developed at NIST. A novel resonator is used to measure the Prandtl number (Pr =eta.Cp/lamda) with uncertainties of about 2%. This paper summarizes our work with these resonators and their applications to numerous gases including very reactive gases used in semiconductor processing.

Proceedings Title

Proceedings of the 17th International Congress on Acoustics, editor Adriano Alippi, v.4 Measurement techniques and transducers

Volume

4

Conference Dates

September 2-7, 2001

Conference Location

Rome

Conference Title

17th International Congress on Acoustics

Pub Type

Conferences

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Keywords

acoustic resonators, Greenspan viscometer, heat capacity, industrial gases, Prantl number, speed of sound, thermodynamic properties, transport properties

Citation

Gillis, K. , Hurly, J. and Moldover, M. (2001), Accurate Measurements of Thermodynamic and Transport Properties of Industrial Gases with Acoustic Resonators., Proceedings of the 17th International Congress on Acoustics, editor Adriano Alippi, v.4 Measurement techniques and transducers, Rome, -1, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=830760 (Accessed October 7, 2025)