A determination of the molar gas constant R by acoustic thermometry in helium

Gavioso, R.M., Ripa, D.M., Steur, P.P.M., Gaiser, C., Truong, D., Guianvarc’h, C., Tarizzo, P., Stuart, F.M. and Dematteis, R. (2015) A determination of the molar gas constant R by acoustic thermometry in helium. Metrologia, 52(5), S274. (doi: 10.1088/0026-1394/52/5/S274)

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 M = (4.002 6032 ± 0.000 0015) g mol-1, with a relative standard uncertainty ur(M) = 0.37×10-6. From these data and traceable thermometry we estimate the speed of sound in our sample of helium at TTPW = 273.16 K and zero pressure to be u0 2 = (945 710.45 ± 0.85) m2 s-2 and correspondingly deduce the value R = (8.314 4743 ± 0.000 0088) J mol-1 K-1 for the molar gas constant. We estimate the value k = R/NA = (1.380 6508 ± 0.000 0015) × 10-23 J K-1 for the Boltzmann constant using the currently accepted value of the Avogadro constant NA. These estimates of R and k, with a relative standard uncertainty of 1.06 × 10-6, are 1.47 parts in 106 above the values recommended by CODATA in 2010.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Stuart, Professor Fin
• Authors: Gavioso, R.M., Ripa, D.M., Steur, P.P.M., Gaiser, C., Truong, D., Guianvarc’h, C., Tarizzo, P., Stuart, F.M., and Dematteis, R.
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Metrologia
• Publisher: Institute of Physics Publishing Ltd.
• ISSN: 0026-1394
• ISSN (Online): 1681-7575
• Copyright Holders: Copyright © 2015 BIPM and IOP Publishing Ltd.
• First Published: First published in Metrologia 52(5):S274
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher