| 摘要 |
PURPOSE:To make it possible to keep up the original characteristic of a humidity sensor for a prolonged period of time by a method wherein when the humidity sensor is cleaned, a fan is stopped to bring the place around the humidity sensor under a windless condition and the humidity sensor is cleaned by heating. CONSTITUTION:An air intake port 7 and an air exhaust port 8 are provided in a heating chamber 6 so that air is sucked into, or discharged from, the heating chamber by means of the fan 4. Further, the humidity sensor 9 is provided adjacent the air exhaust port 8 and a self-cleaning device 9b utilizing thermal energy is arranged in the humidity sensor 9. Thus, when the humidity sensor 9 is cleaned, the air sucking and discharging operations for the heating chamber 6 are suspended by stopping the fan 4 to thereby bring the place around the humidity sensor 9 under the windless condition and the humidity sensor 9 is heated to, and kept at an elevated temperature for a predetermined period of time by the self-cleaning device 9b. As a result, it is possible to keep up the original characteristic of the humidity sensor 9 for a prolonged period of time so that the detection of humidity is carried out accurately at all times to thereby contribute to the automatization of the high frequency heater. |
