水三相点复现的不确定度评定

Evaluation of Uncertainty of Realization of the Triple Point of Water

水三相点是开尔文热力学温度的唯一基准点,也是ITS 90国际温标重要的定义固定点。因此,水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来,中国计量科学研究院研制出一系列高质量的水三相点容器,加强了水三相点的研究,为不确定度的分析提供了更为可靠的实验依据。同时,不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此,根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明,其扩展不确定度为0 16mK(k=2 69,p=0 99)。

The triple point of water (TPW) is not only the sole reference point for Kelvin Thermodynamic Temperature Scale (KTTS), but also a fundamental defining fixed point of International Temperature Scale of 1990 (ITS-90). As a result, the uncertainty evaluation of TPW plays a prominent role in establishing and disseminating ITS-90. In the past three years, the TPW cells of high quality have been developed at the National Institute of Metrology (NIM), and investigation of the TPW has been carried out. Therefore, the research provides a more reliable experimental data to evaluate uncertainty. Also, this uncertainty is a criterion to evaluate the performance of the newly developed cells. According to the experimental results, the uncertainty of realizing the TPW was evaluated. The evaluated results show that the expanded uncertainty is 0.16 mK (k=2.69, p=0.99).