System design and experimental testing of humidity sensor based on condensation method

Air humidity is a basic element of ground and upper air meteorological observation. Measurement of air humidity in the whole range of air temperatures and humidity has been a worldwide problem in the field of atmospheric sounding. By relying on the principle of the condensation method, as well as the rapid developments in microscopic imaging, image recognition and embedded system technology, this article solves key problems such as the technology of condensation mirror design, mirror temperature control and condensate identification. A prototype condensation-type humidity sensor is also successfully developed. Synchronous observations with a humidity standard device and a number of preliminary tests are carried out in different conditions of environment temperature and humidity. The test results show that the deviation of relative humidity between the proposed sensor and the standard device falls within the range of [-2.86, -0.95] %RH, which meets the requirements of business applications for ground meteorological observation.