小型化气体声学温度计的研究

The Investigation of a Miniaturized Acoustic Gas Thermometer

为促进气体声学原级测温技术的实用化发展,基于圆柱气体声学共鸣法测量热力学温度的原理,研制了内径10 mm、外径12 mm、内长40 mm的小型化气体声学温度计,采用优化的声学传感器提高了待测声压强度,开展了常压下常温至782 K的实验测试。对采用声波导管的小型化圆柱腔内常压空气进行测量,结果显示,在782 K时的声学共鸣频率相对标准偏差小于0.2%;修正了边界层及导管扰动后,基于空气声速的热力学关系,以常温为相对法的参考,获得了407~782 K的热力学温度,测量不确定度为0.76~2.93 K(k=1)。该研究为原级气体声学温度计在恶劣或特殊环境下的应用提供了可能。

To promote the practical development of acoustic gas primary thermometry,a miniaturized acoustic gas thermometer with an inner diameter of 10 mm,an outer diameter of 12 mm and an inner length of 40 mm was developed based on the principle of measuring thermodynamic temperature by cylindrical acoustic gas resonant method.An optimized acoustic generator was used to improve the sound pressure intensity.The experiment was carried out from room temperature to 782 K at atmospheric pressure.The results showed that the random deviation of the acoustic resonance frequency in atmospheric pressure air at 782 K is less than 0.2%using acoustic waveguides.After correcting the boundary layer and duct perturbations,the thermodynamic temperature of 407 K to 782 K with room temperature as the reference was obtained with an uncertainty of 0.76 K to 2.93 K(k=1).The investigation provided the possibility for application of the primary acoustic gas thermometer in harsh or special environment.