Analysis and Comparison of Two Different Sensing Techniques for In Situ Coating Thickness Measurements

Abstract Coating thickness is considered to be one of the most important characteristics thermally sprayed coatings. Therefore, it has long been goal able control it. This could achieved by implementing an online, closed-loop control. A prerequisite for such a mechanism feedback signal coating with sufficiently small measurement uncertainty. Optical distance techniques have demonstrated in past produce promising results applications. paper analyzes uncertainty optical technique based on confocal sensors used situ evaluation. As alternative, pneumatically actuated length gauges are also measurement. Both applied during atmospheric plasma spraying samples carousel setup. The two sensing compared reference, destructive method. Pros and cons using different process applications discussed.