Installation of Relative Acoustic Gas Thermometry in the Low Temperature Range from 4.2 to 80 K

A relative acoustic gas thermometry unit for reproducing and transmitting the unit of thermodynamic temperature, i.e., kelvin, in the low temperature range 4.2–80 K was developed and tested. The proposed apparatus differs from previously developed relative acoustic gas thermometry devices in terms of the dimensions of the main resonator unit. Reducing the size of the resonator (cavity diameter) allowed the mass of the cooled parts of the installation to be diminished by several times compared to the mass of such parts of the previously used installation. This significantly reduces the quantities of liquid helium and nitrogen necessary for cooling the resonator, as well as decreases the time of temperature stabilization and, accordingly, the measurement time. The results of verifying the operation of the main systems of the developed installation are presented.