As we know, people have lots of ways to measure the humidity in the ambient .However, it may be still one of the most famous and difficult problems in the world. Such is common methods of the measurement of humidity: dynamic, static, dew point, psychrometer and electronic sensor. This article is mainly about electronic sensor—capacitor sensor.
On the basis of domestic and foreign references, this paper does not only generally state the history and reality of Humidity measurement, but also introduce the tendency and direction of it. Integrated humidity sensor in the humidity measurement has become a trend .in this article we use the integrated humidity sensors to measure the humidity. When the environment changes in humidity, the output of the humidity sensors changes with it linearly, through signal detection and conversion circuit will change the resistance into the corresponding changes in voltage, In accordance with a specific voltage value displayed, the humidity can be known on the corresponding. Further more, this article also concepts the way to use variable capacitor instead of variable capacitance humidity sensor for humidity measurement.