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Determination of the molar mass of argon from a high precision acoustic comparison
Published
Author(s)
XiaoJuan Feng, Jintao Zhang, Michael R. Moldover, Inseok Yang, Mark Plimmer, H. Lin
Abstract
This article describes the accurate determination of the molar mass of a sample of argon gas used for a determination of the Boltzmann constant. The method due to one of the authors [Moldover et al., J. Res. Natl. Bur. Stand. 93, 85-144 (1988)] uses the ratio of the square speed of sound in the gas under analysis and in a reference sample of known molar mass. The results are in good agreement with determinations by gravimetric mass spectrometry, that the fractional difference arising from the two independent procedures is bounded within 0.37×10-6 for the argon sampling from the same container. The uncertainties with both procedures are consistent.
Feng, X.
, Zhang, J.
, Moldover, M.
, Yang, I.
, Plimmer, M.
and Lin, H.
(2017),
Determination of the molar mass of argon from a high precision acoustic comparison, Metrologia, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=922475
(Accessed October 9, 2025)