Patent ID: 7040546

Claim:
A method of positioning a spray apparatus relative to a surface, wherein the spray apparatus emits a liquid spray in an axial direction which impinges upon the surface in a spray pattern, comprising the steps of: directing a single light beam from the spray apparatus toward and onto the surface, wherein the light beam is oriented so as to be non-parallel to the axial direction of the liquid spray, and wherein the single light beam is further oriented so as to strike the surface in a predetermined position relative to and within the spray pattern when the spray apparatus is a predetermined distance from the surface as determined by the angle of the single light beam relative to the axial direction of the liquid spray; positioning the spray apparatus while directing the single light beam toward and onto the surface; operating the spray apparatus simultaneously while directing the single light beam toward and onto the surface, wherein the spray apparatus applies the liquid to the surface in the spray pattern and wherein the single light beam penetrates the spray pattern and strikes the surface within the spray pattern; viewing the position of the light beam within the spray pattern on the surface so as to ascertain whether the light beam is in the predetermined position within the spray pattern and thereby whether the spray apparatus is at the predetermined distance from the surface; and adjusting the distance of the spray apparatus relative to the surface while simultaneously directing the single light beam toward and onto the surface and operating the spray apparatus to emit the liquid toward the surface so as to position the single light beam in the predetermined position relative to and within the spray pattern, and thereby to position the spray apparatus at the predetermined distance from the surface.