Abstract: A solid state electronic controller for humidification devices employs an electronic humidity sensor to create an electronic signal proportional to the humidity in the space to be controlled, and massages or processes this proportional signal to create a cyclic series of time-proportioned control signals to cause the operation of the humidification devices in each cycle for a period proportional to the difference between the sensed humidity and the desired humidity.

Abstract: A doped capacitance humidity sensing element and method of manufacture thereof is provided. The element has a response time in the order of one second and has one electrode formed by an anodizable metal, an anodized layer thereon, conductive, metal atoms deposited in non-short-circuiting mutual relation in the interstices of the anodized layer, the anodized coating layer sealed to contact the particles with an ion-forming material and reduce the porosity of the coating, and a second electrode formed by a moisture-vapor-pervious, electron-conductive layer of metal deposited on the sealed anodized coating on the opposite side from the first electrode, the anodized coating layer being generally pervious to the surrounding gaseous atmosphere and the moisture vapor thereof and the capacitance element presenting an impedance to low frequency sine wave electrical excitation varying inversely and generally proportionally to the relative humidity of the surrounding gaseous atmosphere.