| 摘要 |
PURPOSE:To obtain a humidity detecting device, which can be driven by a DC power source and has a linear output characteristic, by using a humidity sensing body comprising an optically transparent substrate having unevenness and a hygroscopic body. CONSTITUTION:A cap 1 is fixed to an intermediate holder 2 and holds a humidity sensing part 8. A light detecting part 5 is a unitary body comprising a light emitting element 5a and a light receiving element 5b and connected to a display part 7 by a lead wire 6. The humidity body 8 comprises active carbon fiber paper, and an adequate amount of lithium chloride is impregnated as a moisture absorbing agent. At the time of low humidity, light s diffused and reflected by cellulose fiber 8a because of the rough unevenness of the surface, which looks white. The entire fiber looks gray. At high humidity, the moisture is attached to the surface of the cellulose fiber 8a, and a water film W is formed. The surface becomes smooth in apparance and transmits light. The entire active carbon fiber 8b becomes black. In correspondence with the humidity, the color of the temperature sensing body 8 is changed, and the output of the light receiving element 5b is linearly changed. |
