This page summarizes a work presented at the previous year's AVS conference. It revisits the models described in a format using environmental sensors and the monitoring and evolution of an adsorption phenomenon in an ultra-thin layer using real-time ellipsometry.We simultaneously measure the compositions in parts per million (ppm) of carbon dioxide, the moisture content (H2O), as well as the presence of various gases to observe how the optical index of the dielectric SiO2 evolves, assuming an adsorption effect and a modification of its index.