Capacitance humidity sensing element

摘要

A 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.