Dew point measurement using a quartz crystal sensor

According to the problem of atmospheric humidity measurements, the dew point measurement method was proposed based on the resonant and an isolated dew point sensing device was designed. The device has a sensor module to accommodate the quartz crystal sensor and a cooling system. When water condensation produced by the Peltier cooling appears on the quartz crystal, the quartz crystal resonant frequency change suddenly, which tells the beginning moment of condensation, i.e. dew point. The temperature of the quartz surface can be obtained effectively by measuring the temperature of the cold surface of Peltier element and using temperature compensation curves. The measurement results with the proposed device were compared with the reference dew points, though some measurement error was yielded, it is proved that the proposed device is useful for measuring the dew points.