Microstructure movements study by dynamic speckle analysis

In paint and ink industries, no commercial instruments can perform non-intrusive monitoring of the drying process. We propose here an optical instrument, called HORUS(R), that monitors the drying process of any product deposited on any substrate by analyzing micro-structure movement of the product. Most of drying processes have in common that this movement becomes slower with time. On the basis of the "multi-speckle diffusing wave spectroscopy" (MSDWS) technique, we propose here a simple and robust algorithm called ASII for "adaptive speckle imaging interferometry", able to detect in real time the micro-structure agitation by plotting what we call "speckle rate" (SR) as a function of time. We show the hardware configuration and 3 typical experiments made with HORUS(R) film formation analyser.