Patent ID: 7133126
Filing Date: 2006-11-07
Classification: F28F,G01N

Abstract:
1. A method for detecting the presence of a coating on spaced fins having electromagnetic surface properties different than the electromagnetic surface properties of the coating and defining at least one passage between the fins, said method comprising the steps of; propagating electromagnetic rays from a light source through the passage between fins, establishing a predetermined benchmark for the reflected electromagnetic rays with a first detector, reflecting at least some of the electromagnetic rays off the coating on the fins, detecting reflected electromagnetic rays reflected off the coating with a second detector, comparing the reflected electromagnetic rays from the coating to the benchmark, and providing a signal in response to the reflected electromagnetic rays crossing the benchmark, wherein the step of establishing the predetermined benchmark is further defined as detecting direct electromagnetic rays passing through the passage from the source without reflecting off the fins with the first detector and comparing the reflected electromagnetic rays to the direct electromagnetic rays to measure the ratio therebetween.