Influence and treatment of low thermal conductivity substance in infrared imaging testing

The noise produced by a randomly distributed low thermal conductivity (LTC) layer on the outer surface of a metal tube was studied when the corrosion defects on the inner surface of the tube were detected by using infrared imaging technique. The different influences of LTC layer on different heat loading methods were also studied both theoretically and experimentally. A new approach to diminish the high power noise produced by LTC layer was proposed in the end. A numerical method was used to analyze above problem. The main idea of the method was as follows: the temperature distributions reversal mutually may promote to reach minimum if the boundary conditions and power of heat loading device could be controlled properly.