A novel dew point measurement system based on the thermal effect of humidity sensitive thin film

•The dew point sensor based on the thermal effect of humidity sensitive film is reported for the first time.•The sensor has the advantages of simple device and strong anti-interference ability.•The response time of the sensor can be shorten by the software settings. A novel dew point measurement method has been developed by using a temperature sensor covered by humidity sensitive thin film (referred as HSTF). The measurement mechanism is that the mutation of the temperature-time curve caused by the thermal effect of the HSTF can be used to detect dew points. The automatic measurement system of dew point and relative humidity (RH) based on LabVIEW is built. Compared with the existing dew point detection methods, the technique has the advantages of simple device and anti-interference. The experimental data were compared with the reference values with the satisfactory results, relative humidity deviations are less than 1%, the working range is 0–30 °C within 25–85% humidity environment and the maximum response time are less than 65 s which can be further shortened by software. The research provides an effective way for the construction of a simple and automatic dew point measurement system.