Moisture sensor and irrigation control system

摘要

Disclosed is a control system for regulating irrigation to an area of land. The irrigation control system includes a control unit, a photosensor, a timer or controller and a moisture probe for sensing the moisture level in the area to be watered. The control unit is configured to disable power to the system if the moisture level in the area of land exceeds a predetermined level as measured by the moisture probe, which is buried in the watering area. In a preferred embodiment, the moisture probe consists of two electrode plates, preferably manufactured of high purity copper, that are oriented parallel to one another. The electrode plates each have a predetermined length and thickness and are separated by a predetermined distance, each of which are configured to optimize the moisture detecting characteristics of the probe. The control unit applies an electrical potential across the electrode plates such that the resistance of the soil located therebetween varies as a function of moisture content. The control unit measures the soil resistance to thereby determine the moisture content of the soil.