# New measurement of the Boltzmann constant k by acoustic thermometry of helium-4 gas

@article{Pitre2017NewMO, title={New measurement of the Boltzmann constant k by acoustic thermometry of helium-4 gas}, author={Laurent Pitre and Fernando Sparasci and Lara Risegari and C{\'e}cile Guianvarc'h and C Martin and Marc Himbert and Mark Plimmer and Adrien Allard and Benoit Marty and P. Alberto Giuliano Albo and Bo Gao and Michael R Moldover and James B. Mehl}, journal={Metrologia}, year={2017}, volume={54}, pages={856-873} }

The SI unit of temperature will soon be redefined in terms of a fixed value of the Boltzmann constant k derived from an ensemble of measurements worldwide. We report on a new determination of k using acoustic thermometry of helium-4 gas in a 3-litre volume quasi-spherical resonator. The method is based on the accurate determine of acoustic and microwave resonances to measure the speed of sound at different pressures. We find for the universal gas constant R = 8.31 44614 (50) Jmol-1K-1. Using…

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## References

SHOWING 1-10 OF 64 REFERENCES

Improved electronic measurement of the Boltzmann constant by Johnson noise Thermometry

- Physics
- 2014

The unit of thermodynamic temperature, the kelvin, will be redefined in 2018 by fixing the value of the Boltzmann constant, k. The present CODATA recommended value of k is determined predominantly by…

Measurement of the Boltzmann Constant kB Using a Quasi-Spherical Acoustic Resonator

- Physics
- 2011

There is currently great interest in the international metrological community for new accurate determinations of the Boltzmann constant kB, with the prospect of a new definition of the unit of…

Determination of the Boltzmann constant k from the speed of sound in helium gas at the triple point of water

- Physics
- 2015

The Boltzmann constant k has been determined from a measurement of the speed of sound in helium gas in a quasi-spherical resonator (volume 0.5 l) maintained at a temperature close to the triple point…

An improved electronic determination of the Boltzmann constant by Johnson noise thermometry.

- Physics, MedicineMetrologia
- 2017

A new determination of k is provided using a purely electronic approach, Johnson noise thermometry, in which the thermal noise power generated by a sensing resistor immersed in a triple-point-of-water cell is compared to the noise power of a quantum-accurate pseudo-random noise waveform of nominally equal noise power.

A determination of the Boltzmann constant from speed of sound measurements in helium at a single thermodynamic state

- Physics
- 2010

We report on acoustic and microwave measurements made with a purified helium sample maintained close to a single thermodynamic state (Texp ~ 273.16 K, pexp ~ 410 kPa) within a 2.1 L volume stainless…

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

- Materials Science
- 2015

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…

Determination of the Boltzmann constant with cylindrical acoustic gas thermometry: new and previous results combined.

- Physics, MedicineMetrologia
- 2017

The value of kB is substantially unchanged despite significant changes in resonator design and the way in which the cylinder length is determined, and the weighted mean of the determinations is calculated to account for the correlations among the measured quantities.

Determination of the Boltzmann constant by dielectric-constant gas thermometry

- Materials Science
- 2013

Within an international project directed to the new definition of the base unit kelvin, the Boltzmann constant k has been determined by dielectric-constant gas thermometry at PTB. In the pressure…

Acoustic thermometry: new results from 273 K to 77 K and progress towards 4 K

- Materials Science
- 2006

We used a quasi-spherical cavity as an acoustic and microwave resonator to measure the thermodynamic temperatures, T, of the triple points of equilibrium hydrogen, neon, argon and mercury and to…

An improved acoustic method for the determination of the Boltzmann constant at LNE-INM/CNAM

- Physics
- 2009

There is currently great interest in the international metrology community for new accurate determinations of the Boltzmann constant k, with a view to a new definition of the unit of thermodynamic…