QCM露点传感器水粘性影响的抑制方法研究

Study on suppression method for the effect of water viscosity in QCM dew point sensor

为了解决基于主控温式的石英晶体微天平(Quartz Crystal Microbalance,QCM)露点测量系统中冷凝水粘弹特性影响露点识别准确性的问题,对QCM电极进行疏水处理,改善凝结特性,减小水粘性引起的频率耗散,实现液态水质量变化引起的谐振频率偏移测量。在QCM电极上制备静态水接触角为133°±2°的疏水层并对其进行表征,将疏水电极与未经处理的电极用于露点识别实验,并与精密露点仪获得的标准露点进行比对。实验证明,通过疏水处理电极凝结面的方法能够有效提升QCM露点传感器的露点识别精度,为主控温式露点传感器结构的优化设计提供理论和实验依据。

In active temperature⁃controlled dew point measurement based on a quartz crystal microbalance(QCM),the viscoelastic property of liquid water leads to a frequency dissipation which has an effect on the detection accuracy of dew point.Here,the QCM electrode was modified by hydrophobic treatment to improve the condensation form,minimize the dissipation attributed to the water viscosity,and achieve the measurement of resonance frequency offset caused by changes in liquid water quality.A hydrophobic layer with a static water contact angle of 133°±2°was prepared on the QCM electrode and characterized.The hydrophobic electrode and untreated electrode were applied in the dew point recognition experiments,and compared with the standard dew point obtained by a precision dew point meter.The experiments proved that the hydrophobic treatment of the electrode surface can effectively improve the dew point recognition accuracy of the QCM sensor.The optimal approach can provide basis for the design of dew point sensor structure with active temperature control.