US Patent 7280047 Real-time electronic spray deposition sensor

An electronic spray deposition sensor for sensing deposition of liquid on an exterior surface is disclosed. The deposition sensor has a sensing surface comprising a plurality of electrically conductive elements disposed across the sensing surface. The conductive elements are closely spaced apart from each other and insulated from each other on the sensing surface. A comparator circuit is coupled to the conductive elements to detect the presence of liquid at the conductive element. In particular, conductive elements are disposed in an array across the sensing surface such that the presence and location of the liquid on the sensing surface may be determined.