While enamel coating processes are increasingly used in high-end industrial applications, the coating thickness measurement techniques available are limited, unprecise and difficult to implement.
Innovative Laser Photothermal technology is bringing unequalled possibilities for such measurements.
A laser beam is shot on the surface of the coating which is this way heated in a fully nondestructive way. The generated heat wave is then diffusing back and forth within the coating. Then an infrared sensor is collecting the thermal flux coming back from the surface. By measuring the delay between the laser sent and the collected thermal flux, the system can determine the thickness of the coating.
The main advantages of this method are that it is nondestructive, contactless, fast, compact and simple to integrate and implement. But the real industrial advantage comes from the unique ability to measure the enamel layer at all steps of the process : from powder or liquid slurry to dried sintered state and to final fired state. Implementing such measurements at intermediate steps of the enameling allows a faster correction of the process parameters as thickness drifts and nonconformities are detected early.
From cookware enamel to gas pipe anticorrosion layers, this technology has been successfully implemented in various enamelling processes. Indeed, since the laser can heat almost all materials deposited through thermal spray processes, the measurement becomes possible on many coatings and substrates combinations that are else impossible to measure nondestructively.