A determination of the molar gas constant R by acoustic thermometry in helium. (19th August 2015)

• Record Type: Journal Article
• Authors: Gavioso, R M; Madonna Ripa, D; Steur, P P M; Gaiser, C; Truong, D; Guianvarc'h, C; Tarizzo, P; Stuart, F M; Dematteis, R
• Is Part Of: Metrologia. Volume 52:Number 5(2015:Oct.)
• Page Start: S274
• Page End: S304
• Publication Date: 2015-08-19
• Subjects: molar gas constant -- Boltzmann constant -- acoustic gas thermometry -- acoustic resonators -- kelvin -- speed of sound -- helium; Weights and measures -- Periodicals; Weights and Measures -- Periodicals; 530.805
• DOI: 10.1088/0026-1394/52/5/S274
• Languages: English
• ISSNs: 0026-1394

Abstract

Abstract: We have determined the acoustic and microwave frequencies of a misaligned spherical resonator maintained near the temperature of the triple point of water and filled with helium with carefully characterized molar mass g mol −1, with a relative standard uncertainty . From these data and traceable thermometry we estimate the speed of sound in our sample of helium at K and zero pressure to be m 2 s −2 and correspondingly deduce the value J mol −1 K −1 for the molar gas constant. We estimate the value J K −1 for the Boltzmann constant using the currently accepted value of the Avogadro constant N A . These estimates of R and k, with a relative standard uncertainty of 1.06 × 10 −6, are 1.47 parts in 10 6 above the values recommended by CODATA in 2010.