Currently, the CODATA value of the Boltzmann constant is dominated by a single gas-based-thermometry measurement with a relative uncertainty of 1.8 ձ0^-6. This paper describes an electronic approach to measuring the Boltzmann constant that compares Johnson noise from a resistor at the water triple point with a pseudo-random noise generated using quantized ac-voltage synthesis. Measurement of the ratio of the two power spectral densities links Boltzmann's constant to Planck's constant. Recent experiments and detailed uncertainty analysis indicate that the Boltzmann constant can presently be determined using Johnson noise with a relative uncertainty below 10 ձ0^-6, which would support both historic and new determinations.
Citation: Comptes Rendus Physique
Pub Type: Journals
Boltzmann equation, Johnson Noise, Josephson arrays, Noise Thermometry, Temperature