Method for determining humidity transmissivity of optical coating e.g. inorganic dielectric layer coating, on plastic lens, involves entering beam into substrate at front side of substrate, and reflecting beam at rear part of substrate

摘要

The method involves applying a water-impermeable reflector layer (1) on a rear part of a support substrate (2). A coating (3) is applied on a front side of the substrate. The coated substrate is transferred from atmosphere into atmosphere having different moisture contents. Time course of change in water contents of composite of the substrate and the coating by reflection spectroscopy of absorptance band of water in a near infrared spectral region is determined. A measuring beam (4) is entered into the substrate at a front side and reflected at a rear part of the substrate at the layer. The coating is an inorganic dielectric layer or an organic layer.