NIST has developed a quantum-based electronic temperature standard using noise thermometry, which measures Johnson noise in resistors to determine Boltzmann’s constant. This technique could eventually replace traditional temperature fixed points and artifact standards in the ITS-90 scale. The NIST Johnson Noise Thermometer (JNT) provides an electronic measurement of Boltzmann’s constant, which is crucial for the upcoming 2017 redefinition of the SI units. NIST published the first electrical measurement of Boltzmann’s constant in 2010, and a 2014 collaboration with NIM China reduced the uncertainty to ~4 μK/K. Further improvements are expected from new measurements at NIST within the year.
Source: https://www.nist.gov/programs-projects/noise-thermometry
Keywords: Metrology, Thermometry, Temperature, Boltzmann, Quantum
