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.