Investigations Of Humidity Sensors Of Nano-BaTiO₃ And Organic Composite Material

Due to the composite effect and synergism effect, the composite materials have a lot of excellent property that the component materials don't have. Nanocrystalline BaTiO₃ and organic QAR are both good humidity sensing materials. After being made to the composite humidity sensor by different composite methods (bilayer, mixed), the humidity sensing property such as the sensitivity, humidity hysteresis, response-recovery time, impedance property, have changed in some degree, the entire property of the composite film humidity sensor has been inproved. In this paper, the attention focus on the comparison between the composite material and the single material, in order to show the advantage of the composite humidity sensor.The humidity sensing theory is the importance that people focused on. In this paper, direct current method, alternating current method and thermally stimulated current method are used to analysis the sensing theory of the humidity sensing material. Microstructure and chemical composition of the material are studied by SEM, XPS and XRD methods.Usually, after the made of the humidity sensor, a circuit is built according to the data measured, in order to finish the humidity sensing instrument. People always pay attention on the preparation of sensing material and design of the circuit. When the number of the sensor is large, using little measured to instead of the large numbers of data by mathematical fitting is very important. In this paper, a semi-empirical equation model of the resistance-humidity-temperature property of the humidity sensor is built. Take the measured data of one of the samples, using the multivariant linear regression method of SPSS to fitting, the fitting formula corresponding to the sample was built, the results show that the fitting data tally with the original data, the semi-empirical equation model is correct.