| 摘要 |
PURPOSE:To obtain a humidity sensor with limited variation of resitance value by heating a moisture sensing section produced by manufacturing the mixture of a organic fiber tending to swell by absorbing moisture and a conductive fiber into a paper with a heater. CONSTITUTION:A moisture sensing section 1 comprises a carbon fiber paper made up of a cellulose 1a and a carbon fiber 1b. As the degree of the swelling and the deformation of the cellulose fiber 1a due to moisture absorption depends on the hysteresis of the humidity, the resistance of the humidity sensing section 1 after subjected to an extreme dry condition and a high humidity deviates from the normal resistance value. To prevent this, the moisture sensing section 1 is wrapped with a heater 7 and a timer 9 operates a relay 8 intermittently to apply a power to the heater 7 from a power source 10 so that the moisture sensing section 1 and the ambient air will be dried quickly by heat. Thus, the characteristics of the moisture sensing section 1 can be stabilized to minimize the variation in the resistance value. |
