Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin, Germany.
J Chem Phys. 2019 Apr 7;150(13):134303. doi: 10.1063/1.5090224.
The dielectric-constant gas thermometer of Physikalisch-Technische Bundesanstalt (PTB) developed for measuring the Boltzmann constant with a relative uncertainty of 1.9 parts per million was used for determining the virial coefficients of the three noble gases, helium, neon, and argon, at the triple point of water (0.01 C). For this purpose, isotherms were measured up to a maximum pressure of 7 MPa. The evaluation of the highly accurate data by fitting is required to derive an extended working equation for the dependence of the gas pressure on the dielectric constant. The following values have been obtained for the second B and third C virial coefficients, with the standard uncertainties given in parentheses as a multiple of the last digit, considering literature data for the dielectric virial coefficients: helium: B 0.01 C=11.925715 cm/mol, C 0.01 C=113.4958 cm/mol; neon: B 0.01 C=10.994528 cm/mol, C 0.01 C=215.815 cm/mol; argon: B 0.01 C=-21.233144 cm/mol, C 0.01 C=1143.339 cm/mol. These values are compared with the results of the latest ab initio calculations of the second and third virial coefficients.
德国联邦物理技术研究院（PTB）开发的介电常数气体温度计用于测量玻尔兹曼常数，其相对不确定度为 1.9ppm，该温度计用于在水的三相点（0.01°C）测量氦、氖和氩三种惰性气体的第二和第三维里系数。为此，在最高 7MPa 的压力下测量了等温线。需要通过拟合对高精度数据进行评估，以推导出气体压力对介电常数的依赖关系的扩展工作方程。对于第二 B 和第三 C 维里系数，已经获得了以下值，括号中的标准不确定度是考虑文献中的介电维里系数的最后一位数字的倍数：氦：B 0.01°C=11.925715cm/mol，C 0.01°C=113.4958cm/mol；氖：B 0.01°C=10.994528cm/mol，C 0.01°C=215.815cm/mol；氩：B 0.01°C=-21.233144cm/mol，C 0.01°C=1143.339cm/mol。这些值与最新从头算计算的第二和第三维里系数的结果进行了比较。
