Non-Contact Real-Time Film Thickness Gage for Automotive Body Painting Applications

A new automated method of making non-contact real-time automotive coating thickness measurements using laser based ultrasound technology [1] is presented. The system is capable of making wet film measurements on any automotive paint material, predicting the resulting cured film build to a precision of ±1.5 μm. Importantly, the measurement does not require an elaborate calibration to determine the film build; the system should therefore be more reliable and simple to maintain. The system was designed with on-line automotive film thickness measurements as a goal and thus is expected to fit into the painting process with minimal difficulty. The future intent is to use this gage in a closed-loop feedback control system.