Secondary Realization of the IPTS-68 (International Practical Temperature Scale-68) for the Range 273.15 K to 30 K

摘要

The secondary realizations of the International Practical Temperature Scale (IPTS-68) are very useful in industrial and scientific research. In the paper a new method by adding the constraint equations to Kirby's expression was considered for the ranges 273.15 K to 30 K, 40 K and 70 K. The results are very satisfactory, and the accuracy is increased by factor 3 to 5. The differences to the IPTS-68 were estimated to be 2 to 3 mK in the above-mentioned regions.