Thermodynamic Temperature Measurements from the Triple Point of Water up to the Melting Point of Gallium
Thermodynamic Temperature Measurements from the Triple Point of Water up to the Melting Point of Gallium
复制标题
从水三相点到镓熔点的热力学温度测量
DOI：
10.1007/s10765-020-2618-x
复制
发表时间：
2020
影响因子：
2.2
通讯作者：
I. Saito
中科院分区：
文献类型：
--
作者：
J. V. Widiatmo;T. Misawa;T. Nakano;I. Saito
在日本国家计量研究所（NMIJ/AIST）建立了一种新的声波气体测温（AGT）系统，该系统引入了一个由无氧铜制成的1升准球形谐振器（QSR）。采用金刚石车削刀具加工新型QSR的内表面。对压力测量进行了改进，以允许直接测量谐振腔内的气体压力。在700 kPa至50 kPa的压力范围内，通过测量氩气在水三相点处的声速和镓的熔点，对新型AGT系统进行了评价。基于这些声速测量，确定了镓熔点的热力学温度。在283.15 K和293.15 K等温线处进行了声速测量，并确定了相应的热力学温度。根据实测的热力学温度，计算了与1990年国际温标（ITS-90）的温差值（T−T90）及其不确定度。在283.15 K、293.15 K和302.9146 K条件下，得到的（T−T90）分别为1.3±0.7 mK、2.7±0.8 mK和4.1±0.8 mK。发现这些值在估计的不确定度内与目前报告的存在于与当前工作重叠的温度范围内的值一致。
A new acoustic gas thermometry (AGT) system, which introduces a 1-L quasi-spherical resonator (QSR) made of oxygen-free copper, was built at the National Metrology Institute of Japan (NMIJ/AIST). The inner surface of the new QSR was machined using a diamond-turn tool. Improvement in the pressure measurement was introduced to allow direct measurement of the gas pressure in the resonator. The new AGT system was evaluated based on the measurement of the speed of sound in argon at the triple point of water and the melting point of gallium under the pressure range from 700 kPa down to 50 kPa. Based on these speed of sound measurements, the thermodynamic temperatures at the melting point of gallium were determined. The speed of sound measurements at isotherms of 283.15 K and 293.15 K were also conducted, and the related thermodynamic temperatures were determined. Based on the measured thermodynamic temperatureT, the values of difference betweenTand the temperatureT90based on the International Temperature Scale of 1990 (ITS-90), (T−T90), along with the associated uncertainties, were calculated. The (T−T90) obtained in the present work were 1.3 ± 0.7 mK, 2.7 ± 0.8 mK, and 4.1 ± 0.8 mK forT90of 283.15 K, 293.15 K, and 302.9146 K, respectively. These values were found to be in agreement within the estimated uncertainty with the currently reported values that exist in temperature range overlapping with the present work.