微波谐振法应用于高温气体声学温度计的研究OA北大核心CSTPCD
Application of Microwave Resonance Method in High Temperature Acoustic Gas Thermometer
高于335 K的热力学温度T与国际温标ITS-90温度(T90)之间的差异T-T90,是当前国际温度计量前沿研究的重点与难点.基于气体声速获得热力学温度的方法是该温区具有测量不确定度优势的方法,气体声速可通过声学共鸣法测得的声学共振频率和腔体尺寸获得.微波谐振法是高温区实时、原位获得腔体尺寸和热膨胀性的技术路线.通过优化高温气体声学热力学温度测量装置,提升温度和压力稳定性;采用自研的耐高温微波传感器,测量了 335 K至493 K圆柱腔内的微波谐振频率,相对标准偏差为(2~13)× 10-8;通过微波谐振频率获得了腔体尺寸随温度的变化关系,验证了几何尺寸的稳定性;同时实时获得圆柱腔内气体的折射率和压力,用于分析流动气路产生的压差.研究结果可为精密测定335 K以上T-T90提供重要基础.
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.
朱章睿;邢力;冯晓娟;张金涛;孙坚
中国计量大学机电工程学院,浙江杭州 310018||中国计量科学研究院热工计量科学研究所,北京 100029中国计量科学研究院热工计量科学研究所,北京 100029中国计量大学机电工程学院,浙江杭州 310018
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
temperature measurementacoustic gas thermometrythermodynamic temperaturemicrowave resonance methodthermal expansionrefractive indexpressure
《计量学报》 2024 (009)
1249-1256 / 8
国家重点研发计划(2021YFF0603804);国家自然科学基金(52176170)
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