| 摘要 |
PURPOSE:To suppress excessive input to the change of a resistance value by arranging a pair of electrodes oppositely, making electric flux from one electrode to the other electrode alternative current (AC) and using the AC input obtained from the other electrode as a driving input source to a humidity sensitive element. CONSTITUTION:A tuning fork 3 is excited by an oscillation circuit (not shown in figure), electric flux (a) directing from a fixed electrode 1 to a fixed electrode 2 through a gap (d) between leg parts 31, 32 of the tuning fork 3 is chopped in accordance with oscillation frequency to generate AC voltage and the AC voltage is used as the driving input source of the humidity sensitive element 4. Consequently, characteristics deterioration and high resistance due to polarization in case of the impression of DC voltage can be suppressed and excessive input due to the variation of a resistance value over a wide range from a low temperature to a high temperature and a high humidity can be suppressed. |
