A New Type of Hydrophilic QCM Dew Point Sensor

In order to increase the sensitivity and enhance the recognition feature during the measurement of the dew point based on the active temperature-controlled quartz crystal microbalance (QCM) dew point sensor, a new hydrophilic QCM dew point sensor and dew point recognition method were proposed in this paper. In the sensor, the QCM coating with a reduced graphene oxide (rGO) thin film was used as the sensitive unit. Dew point recognition method based on calculating the second derivative of the frequency variation curve was proposed to get the accurate dew point values. Experiments based on the designed sensor was carried out under different dew point conditions and the dew points were recognized by using the designed method. The results showed that the designed sensor had obvious dew point recognition feature and could achieve acceptable measurement error as less than 0.31°C compared with the precise dew point meter MICHELL 84000.