Improved apparatus to determine the Boltzmann constant using a large quasi-spherical acoustic resonator

Author

Pitre, L. ; Sparasci, F. ; Risegari, L. ; Guianvarc´h, C. ; Plimmer, M.D. ; Himbert, M.E.

Author_Institution

Lab. Commun de Metrol., LNE-CNAM, La Plaine St. Denis, France

fYear

2014

fDate

24-29 Aug. 2014

Firstpage

206

Lastpage

207

Abstract

There is currently great interest in a new definition of the SI unit of temperature based on a fixed value of the Boltzmann constant k. This paper describes work towards an improved determination of k from the measurement of the speed of sound in argon in a quasi-spherical resonator at constant temperature near 273.16 K. The speed is extracted from acoustic resonance frequencies extrapolated to ideal gas behavior while the dimensions of the resonator are determined from microwave resonance frequencies. We outline key aspects of the experiment namely thermometry and pressure measurement, acoustic and microwave resonances and gas handling.

Keywords

acoustic resonators; acoustic variables measurement; argon; constants; microwave resonators; pressure measurement; temperature measurement; Ar; Boltzmann constant; argon; gas handling; ideal gas behavior; microwave resonance frequencies; pressure measurement; quasispherical acoustic resonator; speed of sound; thermometry; Acoustic measurements; Acoustics; Argon; Frequency measurement; Microwave measurement; Resonant frequency; Temperature measurement; Acoustic resonance; Boltzmann constant; Microwave resonance; Thermometry;

fLanguage

English

Publisher

ieee

Conference_Titel

Precision Electromagnetic Measurements (CPEM 2014), 2014 Conference on

Conference_Location

Rio de Janeiro

ISSN

0589-1485

Print_ISBN

978-1-4799-5205-2

Type

conf

DOI

10.1109/CPEM.2014.6898331

Filename

6898331