We review the principles, techniques and results from primary acoustic gas thermometry
(AGT). Since the establishment of ITS-90, the International Temperature Scale of 1990 …

The present definition of the kelvin links the unit of temperature with a material property,
namely the triple point temperature of water. It would be more consistent with the current …

The adiabatic, relativistic, and quantum electrodynamics (QED) contributions to the pair
potential of helium were computed, fitted separately, and applied, together with the …

This review gives a brief introduction to the principles of microwave measurements of the
complex permittivity of materials. The fundamentals of reflection, transmission and resonant …

Recent advances regarding the interplay between ab initio calculations and metrology are
reviewed, with particular emphasis on gas-based techniques used for temperature and …

Using a quasispherical, microwave cavity resonator, we measured the refractive index of
helium to deduce its molar polarizability A ε in the limit of zero density. We obtained (A ε …

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

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 …

We have developed a new low-pressure sensor which is based on the measurement of
(nitrogen) gas refractivity inside a Fabry–Perot cavity. We compare pressure determinations …

The redefinition of the kelvin has increased focus on thermometry techniques that use the
newly fixed value of the Boltzmann constant to realize thermodynamic temperature. One …