Measurement method for very low frost point using quartz crystal microbalance dew-point sensor

摘要

A measurement method for ultra low dew point using a quartz crystal microbalance dew point sensor is provided to determine exact dew point by measuring resonant frequency of a crystal oscillator according to temperature change and correcting temperature and resonant frequency. A quartz crystal microbalance dew point sensor comprises a crystal oscillator(10), a crystal oscillator holder(30), a heat sink(20), and a liquid nitrogen feeding unit(50). The crystal oscillator holder is contacted with the edge of the crystal oscillator. On the single-side of the crystal oscillator holder, a platinum resistance thermistor is attached. The heat sink controls the temperature of the crystal oscillator and the crystal oscillator holder using the liquid nitrogen. The liquid nitrogen feeding unit automatically supplies the liquid nitrogen to the heat sink. The quartz crystal microbalance dew point sensor measures the change of the resonant frequency and the temperature of the platinum resistance thermistor according to the temperature change of the crystal oscillator and determines the dew point.