基于Colpitts振荡电路的露点识别机理的验证

Verification of the Method of Dew Point Recognition Based on Colpitts Oscillating Circuit

针对大气湿度测量问题,首次提出一种基于Colpitts振荡电路的露点识别方法.把Colpitts电路中的石英晶体作为湿敏元件,由于考比兹电路不能驱动处于液相环境下的石英晶体振荡,因此用半导体制冷器对石英晶体进行制冷直到有结露产生时使得石英晶体处于液相环境中,当凝结发生时将使整个考比兹电路停止振荡,同时获取停振时刻石英晶体表面温度从而达到对露点的识别和测量,可以根据获取的露点温度得到环境的相对湿度.通过对Colpitts电路特性以及石英晶体导纳特性的分析,结合试验数据对比,可以从定性的角度验证此方法和装置对湿度测量的有效性与准确性,此结果对基于谐振电路湿敏传感机理定量分析以及新型谐振式露点仪的研发具有重要理论意义.

Aiming at the problem of atmospheric humidity measurement,the paper proposes a method to measure dew point based on sensitive circuit for the first time.We used the quartz crystal in the Colpitts circuit as the humidity sensitive element.Because the Colpitts circuit cannot drive quartz crystal oscillate in liquid environment,so we used semiconductor cooler to cool the quartz crystal until the dew is generated when the quartz crystal is in the liquid phase environment.The Colpitts oscillation circuit stopped when the condensation occurs,at the same time got the temperature of quartz crystal surface the moment vibration stops so as to recognize and measure the dew point.Through the analyzed of the characteristics between the Colpitts circuit and the quartz crystal admittance,then combined with experimental data comparison,it proved that the proposed method for identifying the validity and accuracy of humidity from the qualitative point.The result is of important practical significance for further quantitative analysis and researching and developing sensitive circuit type dew point instrument.