The thermal metrology community is considering revising the International Temperature Scale of 1990 (ITS-90), motivated by the opportunity to improve the thermodynamic accuracy, reproducibility, and ease of use of the scale, as well as health and safety concerns with the use of mercury in the current scale. This paper considers the mathematical structure of the Standard Platinum Resistance Thermometer (SPRT) interpolations of the ITS-90 and identifies (i) mathematical features that are advantageous and should be retained, (ii) opportunities for improvements, and (iii) the research required to maximise the benefits from such improvements. The improvements considered include minor adjustments that leave ITS-90 intact, numerical adjustments to reference resistance ratios that preserve the structure of ITS-90, fixed-point replacements, new subranges, and large-scale changes in the mathematical structure of the interpolations. A significant research effort will be required to implement some of the changes. Overall, an improvement in the thermodynamic accuracy by a factor of about 10 is relatively easily realised, but improvements in reproducibility of the scale of even a couple of tens of percent will be hard won. For most users, the costs and inconvenience of a substantial scale revision may outweigh the benefits.

中文翻译：

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修正温标中的标准铂电阻温度计插值

热计量学界正在考虑修订 1990 年国际温标 (ITS-90)，其动机是有机会提高热力学精度、再现性和易用性，以及使用温标的健康和安全问题当前规模的汞。本文考虑了 ITS-90 的标准铂电阻温度计 (SPRT) 插值的数学结构，并确定了 (i) 有利且应保留的数学特征，(ii) 改进机会，以及 (iii) 所需的研究以最大限度地利用此类改进的好处。考虑的改进包括保持 ITS-90 不变的微小调整、对参考电阻比的数值调整以保留 ITS-90 的结构、定点替换、新子范围、以及插值的数学结构的大规模变化。需要进行大量的研究工作来实施一些更改。总的来说，将热力学精度提高约 10 倍相对容易实现，但即使是几十个百分点的规模再现性提高也很难实现。对于大多数用户来说，大规模修订的成本和不便可能会超过收益。