The IMERAPlus joint research project for determinations of the Boltzmann constant

J. Fischer, B. Fellmuth, C. Gaiser, T. Zandt, L. Pitre, S. Briaudeau, F. Sparasci, D. Truong, Y. Hermier, R.M. Gavioso, C. Guianvarc'H, P.A.G. Albo, A. Merlone, F. Moro, M. De Podesta, G. Sutton, R. Underwood, G. Machin, D. Del Campo, J. Segovia PurasD. Vega-Maza, J. Petersen, J. Hald, L. Nielsen, S. Valkiers, B. Darquié, C. Bordé, C. Chardonnet, C. Daussy, L. Gianfrani, A. Castrillo, P. Laporta, G. Galzerano

Research output: Chapter in Book/Report/Conference proceedingConference contribution

7 Citations (Scopus)


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 languageEnglish
Subtitle of host publicationProceedings of the Ninth International Temperature Symposium
EditorsChristopher W. Meyer
PublisherAIP Publishing
Number of pages11
ISBN (Print)9780735411784
Publication statusPublished - Sep 2013
Event9th International Temperature Symposium (ITS9) - Los Angeles, United States
Duration: 19 Mar 201223 Mar 2012

Publication series

NameAIP Conference Proceedings
PublisherAIP publishing


Conference9th International Temperature Symposium (ITS9)
CountryUnited States
CityLos Angeles


  • fundamental constant
  • Boltzmann constant
  • International System of Units
  • primary thermometry

Fingerprint Dive into the research topics of 'The IMERAPlus joint research project for determinations of the Boltzmann constant'. Together they form a unique fingerprint.

  • Cite this

    Fischer, J., Fellmuth, B., Gaiser, C., Zandt, T., Pitre, L., Briaudeau, S., Sparasci, F., Truong, D., Hermier, Y., Gavioso, R. M., Guianvarc'H, C., Albo, P. A. G., Merlone, A., Moro, F., De Podesta, M., Sutton, G., Underwood, R., Machin, G., Del Campo, D., ... Galzerano, G. (2013). The IMERAPlus joint research project for determinations of the Boltzmann constant. In C. W. Meyer (Ed.), TEMPERATURE: ITS MEASUREMENT AND CONTROL IN SCIENCE AND INDUSTRY, VOLUME 8: Proceedings of the Ninth International Temperature Symposium (pp. 2-12). (AIP Conference Proceedings; Vol. 1552, No. 1). AIP Publishing.