Get 79-2020 State Primary Special Standard of the Unit of Specific Heat of Solids in the Temperature Range from 2 to 300 K

The paper shows the necessity and relevance of performing precise specific heat measurements for the existing and newly synthesized substances and solids at low temperatures. The authors present GET 79-2020 State Primary Special Standard of the unit of specific heat of solids in the temperature range from 2 to 300 K, describing its design, operating principle, and the results of metrological examination. GET 79-2020 comprises the developed reference throttling cryostat and a cell for measuring specific heat that ensure efficient and prompt cooling of the test sample, as well as a reduction in uncontrolled heat fluxes, during measurement. GET 79-2020 can realize the unit of specific heat of solids within the range of 0.03–718 J/(kg·K) and the temperature range of 2–300 K. A method for measuring specific heat using the developed cell is described. The authors examine the metrological characteristics of GET 79-2020, estimating the uncertainty budget for realizing the unit of specific heat of solids. The obtained results extend the temperature range of measurements, expanding the fleet of working standards (measures) for heat capacity measuring instruments, verified using GET 79-2020.