The use of Bismuth for the manufacture of means of transmitting units of specific heat in the temperature range 240–520 K

The currently used data on the heat capacity of Bismuth were obtained in the 1980s. Different methods and different measuring equipment were used to obtain these data. The data on heat capacity published in different sources differ by a value greater than the permissible error of the measuring instruments and techniques used. There is no information in the available sources about the applied methods of registration of input data and statistical processing methods. It is impossible to assess the reliability of the Bismuth heat capacity measurements based on this situation. Bismuth in its pure form and in alloys is widely used in industry and engineering. The unreliability of its heat capacity leads to several problems. The fi rst is the lack of reference values for the specifi c heat capacity of Bismuth, which are necessary for the input control of materials in the electrical industry. The second is overestimation of tolerances during design calculations. The third is the reduction of the working ranges of alloys. The article presents the results of a study of the specifi c heat capacity of pure Bismuth in the period 2021–2025. The stability of reproducing the specifi c heat capacity of Bismuth during storage without special conditions and the possibility of using this material to control temperature scales and measuring instruments for thermal analysis are evaluated. The results obtained will be useful to metrologists and users of measuring instruments for complexthermal analysis, materials scientists investigating the thermophysical properties of semi-metals and layered structures, developers of the electrical and instrument engineering industry, technologists of the chemical and pharmaceutical industries

thermophysical properties, heat capacity, Bismuth, stability, power scale, measuring instruments, thermal analysis