关键词：露点测量;科耳皮兹电路;石英晶体
摘 要：Based on the phenomenon that Colpitts circuit cannot drive quartz crystal in liquid phase environment,this paper studies the wet sensitive characteristics of Colpitts oscillation circuit.And we designed a device used as humidity sensor.Peltier element was used to cool quartz crystal until dew occurred and quartz crystal worked in the liquidenvironment.Colpitts circuit stopped oscillation when dew occurred.At the same time the temperature of crystal surface was measured and the temperature was approximately regarded as the dew point.Through the theoretical analysis of Colpitts circuit characteristic and the humidity sensing properties of quartz crystal admittance,then combined with experimental data comparison,the wet sensitive characteristics of Colpitts circuit was proved to be feasible and accurate for dew point recognition from the qualitative point.The result is of practical importance for further quantitative analysis and developing sensitive circuit type dew point instrument.