Development of thermodynamic temperature measurement technique based on quantum standards at NMIJ/AIST

We have started development of a thermodynamic temperature measurement system based on Johnson-Nyquist equation. In this measurement power spectrum density of a resistor is measured using electrical quantum standards as references. This thermometer will play an important role in determination of the Boltzmann constant, comparison between thermodynamic temperature and definitions in International Temperature Scale of 1990, and measurement of arbitrary temperature in a wide temperature range.