Method of Increase Humidity Sensing Accuracy
ZHANG Shengfu1,ZHANG Peng2(1.North China Spaceflight Industry College Electronics Engineering Department,Langfang065000,China;2.The Langfang Food Engineering School,Langfang 065000,China)
The macromolecule humidity sensing of thin film is a humidity sensing to use at usually. It's postulate is to make a parallel board electric capacity from use smoke plate a flat smallest hole pole on the surface of the macromolecule of thin film. When opposite degree of humidity for the measured gas be changed, the macromolecule of thin film in moisture absorption or moisture doff its mind electricity constant ε changing, this make the capability of the humidity sensing capacitance and the relative humidity of the measured gas changed as well as direct proportion. When we translate the variety of capacitance into frequency signal we can measure relative humidity. Usually the precision of the humidity sensing capacitance changed, parameter's coherence worse. If we adopt difference frequency measure in hardware, at the same time use relevant software do data processing; we can avoid infection for measure precision from sensor mediate circuit power supply wave?the change of condition temperature,the distributing capacitance in degree.
【CateGory Index】： TH765