计量学报2024，Vol.45Issue(9)：1249-1256,8.DOI:10.3969/j.issn.1000-1158.2024.09.01
微波谐振法应用于高温气体声学温度计的研究
Application of Microwave Resonance Method in High Temperature Acoustic Gas Thermometer
摘要
Abstract
The difference between the thermodynamic temperature T above 335 K and the International Temperature Scale ITS-90 temperature(T90)T-T90,is currently the focus and difficulty of frontier research in international temperature metrology.Acoustic gas thermometry,based on the determination of theremperature from the speed of sound in gases,is one of the promising methods for this temperature range.The speed of sound in gases could be measured from acoustic resonant frequency and the inner dimension of the cavity.Microwave resonance method is a technical route for real-time and in-situ measurement of cavity size and thermal expansion at high-temperature.We optimized the high-temperature acoustic gas thermometry system to improve the temperature and pressure stability.Homemade high-temperature microwave cable and sensor were used for the measurement of microwave resonant frequencies in a cylindrical cavity from 335 K to 493 K with a relative standard deviation of(2～13)×10-8.The variation of the cavity size with temperature was obtained through microwave resonance frequencies.The stability of geometric of the cylindrical cavity was acceptable.Then the refractive index and pressure of the gas inside the cylindrical cavity were determined for analyzing the pressure difference from flowing gas.These results are helpful for future determination of T-T90 above 335 K with low uncertainties.关键词
温度计量/气体声学温度计/热力学温度/微波谐振法/热膨胀/折射率/压力Key words
temperature measurement/acoustic gas thermometry/thermodynamic temperature/microwave resonance method/thermal expansion/refractive index/pressure分类
通用工业技术引用本文复制引用
朱章睿,邢力,冯晓娟,张金涛,孙坚..微波谐振法应用于高温气体声学温度计的研究[J].计量学报,2024,45(9):1249-1256,8.基金项目
国家重点研发计划(2021YFF0603804) （2021YFF0603804）
国家自然科学基金(52176170) （52176170）
