| 摘要 |
PURPOSE:To reduce labor and cost of maintenance for the detecting part of a hygrometer by assemblying a humidity sensing element and an electrostatic capacity correction resistor into a unit and detatchably forming this unit within a circuit in the detecting part of the hygrometer. CONSTITUTION:A humidity sensing device comprises a supporting socket 1, a ring packing 2, a time constant output apparatus 3, a ring packing 4, a humidity sensor unit 5 and a gas permeable cover 6. The sensor unit 5 is provided with a humidity sensing element 34 of macromolecular film in a chamber surrounded by a gas permeable cylinder cell 18 and a gas permeable protector cap 19 and a correction electric resistor 32 fixed in a molding 33. The electric resistor 32 is formed a circuit of a predetermined time constant in an oscillation circuit of the time constant output apparatus 3, being assembled together with the electrostatic capacitor characteristic of the humidity sensing element 34. The above described constitution gives the sensor unit 5 interchangeability thereby the sensor unit can be more costsaving in maintainance. |
