The Consultative Committee for Thermometry and NIST have redefined the kelvin, the standard unit for temperature, to rely on fundamental constants rather than physical materials. While the official definition has changed, the practical impact is minimal because existing tools remain highly accurate and reliable. This transition allows current measurement methods to continue without immediate disruption while newer technologies are developed.
New technologies are being created to base temperature measurements on quantum mechanics rather than physical materials. These include systems that detect tiny electrical fluctuations or changes in light frequency, as well as a NIST prototype using quantum mechanical motions in tiny mechanical systems. These methods aim to provide higher precision and remove dependence on specific materials.
Although these quantum methods are promising, they are still under development and not yet widely implemented. Current standard thermometers will continue to be used in the near future, as new technologies need time to prove they can replace existing reliable tools. Full adoption of these quantum protocols is expected as measurement science continues to evolve.
Source: https://www.nist.gov/si-redefinition/kelvin/kelvin-future-realization
Keywords: Johnson noise thermometry, photonic thermometry, quantum thermometer
