Investigation of ITS-90 Inconsistencies in Overlap Region of the Water-indium, Water-tin, and Water-zinc Sub-ranges

摘要

One of the significant uncertainties in Standard Platinum Resistance Thermometer (SPRT) calibration by fixed-points method is Type I non-uniqueness (sub-range inconsistencies). Sub-ranges water-tin (W (9) ) and water-indium (W (10) ) lies in the water-zinc (W (8) ) sub-range of the International Temperature Scale of 1990. Therefore, three sub-range inconsistencies [W (8) and W (9) (SRI (8-9) ), W (8) and W (10) (SRI (8-10) ), and W (9) and W (10) (SRI (9-10) )] occur. This paper investigated these inconsistencies using the calibration data of 12 SPRTs from six manufacturers. The result shows that the magnitude of the inconsistency for SRI (8-9) , SRI (8-10) , and SRI (9-10) are about 2.5, 2.2 and 1.8 mK, respectively.