Patent ID: 7250087

Claim:
A method for evaluating the operating status of an individual spray nozzle of a cleaning device from the exterior of a vessel wherein said cleaning device is a rotating spray head located within said vessel and includes a plurality of spray nozzles that rotate together about a common axis, said method comprising the steps of: capturing sound signals from the exterior of said vessel when the cleaning device is in operation; storing said sound signals as frequency patterns; isolating sound peaks from said frequency patterns and separating said sound peaks into a number of different groups wherein the number of said groups is equal to the number of spray nozzles wherein each sound peak in a pattern is associated with a different one of said nozzles; storing said sound peaks in a plurality of buffers, the number of said buffers being equal to the number of said spray nozzles; comparing said plurality of sound peaks in each buffer with the plurality of sound peaks in each of the other buffers and identifying any of said plurality of sound peaks that substantially differs from the remaining plurality of sound peaks, and outputting indicia of the operating status of said cleaning device based upon said identification.