Structure Optimization and Performance Evaluation of Dew Point Sensors Based on Quartz Crystal Microbalance

In order to address the instability of the fixation in the temperature controlled quartz crystal microbalance (QCM), a new sensor structure was proposed and evaluated under different dew point conditions. The QCM was fixed by two O-ring thermal gaskets placed on both sides symmetrically with the constraining forces. Simulations by finite-element modeling were performed to determine the O-ring thermal gasket dimensions and the constraining forces. Results showed that the QCM structure had steady vibration properties with high heat transfer rates, when the constraining force value was less than 0.06 N, and the O-ring thermal gasket width ranged from 0.6 to 1.0 mm with a thickness of 0.5 mm. Experiments were carried out to evaluate the accuracy, stability, and repeatability of the sensor and results showed that the designed sensor had good performances compared with the standard instrument.