Abstract
To provide new determinations of the Boltzmann constant, k, which has been asked for by the International Committee for Weights and Measures concerning preparative steps towards new definitions of the kilogram, the ampere, the kelvin and the mole, an iMERAPlus joint research project has coordinated the European activities in this field. In this major European research project the Boltzmann constant has been determined by various methods to support the new definition of the kelvin. The final results of the project are reviewed in this paper. Determinations of the Boltzmann constant k were achieved within the project by all three envisaged methods: acoustic gas thermometry, Doppler broadening technique, and dielectric constant gas thermometry. The results were exploited by the interdisciplinary Committee on Data for Science and Technology (CODATA) in their 2010 adjustment of recommended values for fundamental constants. As a result, the CODATA group recommended a value for k with a relative standard uncertainty about a factor of two smaller than the previous u(k)/k of 1.7×10−6.
Original language | English |
---|---|
Title of host publication | TEMPERATURE: ITS MEASUREMENT AND CONTROL IN SCIENCE AND INDUSTRY, VOLUME 8 |
Subtitle of host publication | Proceedings of the Ninth International Temperature Symposium |
Editors | Christopher W. Meyer |
Publisher | AIP Publishing |
Pages | 2-12 |
Number of pages | 11 |
ISBN (Print) | 9780735411784 |
DOIs | |
Publication status | Published - Sept 2013 |
Event | 9th International Temperature Symposium (ITS9) - Los Angeles, United States Duration: 19 Mar 2012 → 23 Mar 2012 |
Publication series
Name | AIP Conference Proceedings |
---|---|
Publisher | AIP publishing |
Number | 1 |
Volume | 1552 |
Conference
Conference | 9th International Temperature Symposium (ITS9) |
---|---|
Country/Territory | United States |
City | Los Angeles |
Period | 19/03/12 → 23/03/12 |
Bibliographical note
AcknowledgementsThe authors gratefully acknowledge both a personal and a professional debt to Michael Moldover at NIST and Jim Mehl (formerly at NIST and the University of Delaware). The authors are grateful to Wladimir Sabuga and Otto Jusko at PTB who designed, put into operation and characterized the pressure balances. Many other research institutions and private companies have contributed to the project outcome. Special thanks go to: Cranfield University (UK), Université du Maine (F), Scottish Universities Environmental Research Centre (UK), Savimex (F),
Rial Vacuum (I), Linde Gas (G), and DH Instruments (USA).
The research within the EURAMET Joint Research Project received funding from the European Community’s Seventh Framework Programme, iMERAPlus, under Grant Agreement No 217257 which is gratefully acknowledged.
Keywords
- fundamental constant
- Boltzmann constant
- International System of Units
- primary thermometry