准绝热密封氩三相点复现装置

The Sealed-type Argon Triple-point Device to Calibrate Long-stem Thermometers in Quasi-adiabatic Conditions

氩三相点作为国际温标ITs—90的重要低温固定点，在国家基准量值传递中有着重要的意义。中国计量科学研究院研制了基于准绝热原理的密封型氩三相点装置，能够对长杆铂电阻温度计进行氩三相点高精度复现，并且通过开发自动控制与测量软件实现了实验过程自动化测量与控制。实验结果表明，使用新研制的密封氩三相点装置使氩三相点的温坪时间提高到23h以上，其中在16h的温坪变化在0．2mK以内，同时温坪复现性达到0．1mK以内，成功解决了恒定热流法氩三相点复现过程中温坪时间短、复现难度大等问题，保证国家基准量值传递的准确性。

The argon triple-point, one of the required reference fixed points at the low-temperature range in the international temperature scale of 1990 （ ITS---90）, is significant in the verification of national primary standard. A new type of sealed argon triple-point device, used to calibrate long-stem platinum resistance thermometers （SPRTs）in quasi-adiabatic conditions, is developed by National Institute of Metrology. The software used for automatic measuring and instrument controlling is developed as well. The results show that the plateau time of the new type of sealed argon triple-point device can reach above 23 hours,and the difference of the plateau is within 0. 2 mK during 16 hours. The reproducibility is 0. 1 inK. The new device successfully eliminates defects of the short plateau time and the great difficulty in the realizing of the argon triple-point with a continuous heat flux method. This research improves the argon triple-point device, and ensures the accuracy of the temperature verification.