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声学温度计通过声速的精密测量得到热力学温度,是目前测量热力学温度不确定度最小的方法之一。压电陶瓷传感器结合端盖薄膜结构的声学传感器和传统麦克风传感器相比能够显著提高圆柱共鸣腔的共振频率测量信噪比。在圆柱共鸣腔中,纯轴向声学模式共振峰的幅值和信噪比随着压电陶瓷传感器驱动电压的增加而增加。压电陶瓷传感器驱动电压的变化对共振峰的频率和半宽影响较小,不会引起额外频率扰动。共振频率的随机偏差在气体压力低于150 kPa时随压电陶瓷传感器驱动电压升高逐渐减小;在气体压力高于150 kPa时驱动电压的影响不明显。该研究对于提高采用圆柱定程干涉法声学温度计测量热力学温度的精度具有重要的意义。
Acoustic thermometers obtain the thermodynamic temperature through the precise measurement of the sound velocity, which is one of the methods for measuring the thermodynamic temperature with the minimum uncertainty. Piezoceramic Sensors The acoustic sensors combined with the cap film structure measure the signal-to-noise ratio of resonant resonators in a cylindrical resonator significantly better than traditional microphone sensors. In a cylindrical resonance cavity, the amplitude and signal-to-noise ratio of the pure axial acoustic mode formant increases as the driving voltage of the piezoceramic sensor increases. The change of driving voltage of piezoelectric ceramic sensor has little influence on the frequency and half-width of the formant, and will not cause additional frequency disturbance. The random deviation of the resonance frequency decreases with the increase of the driving voltage of the piezoceramic sensor when the gas pressure is lower than 150 kPa. The effect of the driving voltage is not obvious when the gas pressure is higher than 150 kPa. This study is of great significance to improve the accuracy of measuring the thermodynamic temperature by the acoustic method of cylindrical fixed-path interferometry.