| 摘要 |
<p>PURPOSE:To obtain an excellent responding property and a high aging property, by providing a pair of electrodes and using one of them also as a heater. CONSTITUTION:An electrode 2 and another electrode 3, which serves also as a heater, are provided on a base board 5. A humidity sensor 11 made of a metal oxide semiconductor connected with lead wires 4 is provided. A circuit is composed of the humidity sensor 11, a fixed resistance 12, a voltmeter 13 and a transformer 14. When the resistance of the humidity sensor 11 changes, an electrical current flowing through the transformer 4, the humidity sensor 11 and the fixed resistance 13 varies. Therefore, the value pointed by the voltmeter changes. When the humidity sensor 11 is in operation, it is heated at a constant temperature by the heater 3 so that adsorbed excessive water molecules go off the surface of the sensor. This results in always stabilizing the characteristic of the sensor.</p> |
