双圆柱微波谐振测量热力学温度的研究

Thermodynamic Temperature Measurement by Microwave Resonance at Two Cylinders

热力学温度是客观世界真实的温度,是制定国际温标的基础。本文针对目前热力学温度测量技术相对滞后于物理学发展、测量周期长和难以实用化的现状,结合量子力学的从头算理论和双圆柱微波谐振方法测量了313 K附近的热力学温度,测量得到的热力学温度值和ITS90国际温标的温度之间的差异为2.40 mK,测量的相对标准不确定度为14×10^(-6)。进一步分析了测量不确定的来源,预期在300～400K测量热力学温度的相对标准不确定度能达到5×10^(-6)。

Thermodynamic temperature is one of the most important physical parameters related to energy equilibrium and energy exchange.The International Temperature Scale of 1990（ITS90） was also based on the thermodynamic temperature measurements.In this paper,we combined the new results from ＂ab initio＂ theory and microwave techniques to develop new method for measuring thermodynamic temperature.The experimental system was also built based on the two-cylinder microwave resonance method.The thermodynamic temperature around 313 K was measured and difference between the thermodynamic temperature and the temperature calibrated by ITS99 is 2.40 mK.The relative standard uncertainty was estimated to be 14×10^（-6）.The microwave modes consistency was the biggest uncertainty source.The uncertainty for the thermodynamic temperature measurement in the range from 300 to 400 K will be 5×10^（-6） after the modes consistency problem was fixed.