Capacitance humidity sensing element
Patent 4305112 Issued on December 8, 1981. Estimated Expiration Date: 
October 31, 1999. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
October 31, 1999. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2627645 2884593 3360701 3550941 3582728 InventorsApplicationNo. 06/090051 filed on 10/31/1979US Classes:361/286, Humidity73/335.04CapacitanceExaminersPrimary: Goldberg, Elliot A.Attorney, Agent or FirmInternational ClassG01N 27/22 (20060101)Foreign Application Priority Data1978-11-06 DEAbstractA multi-layered capacitive humidity sensing element having a carrier material separated from a water vapor permeable, electrically conductive coating by an insulating layer which is humidity sensitive, and a method for its manufacture is provided. A metal foil is utilized as the carrier material serving both as a support frame and as an electrically conductive layer. A thin gold layer is applied to the insulating layer, which is formed out of a synthetic material. The gold layer is sufficiently permeable to allow water vapor to freely diffuse into the synthetic layer from the surrounding atmosphere, yet remains thick enough to function as an electrically conductive outer layer. The sensing element thus constructed has both a short response time and an improved simplicity of manufacture. | |
