Hydrogenated amorphous carbon coating/barrier layer`s thickness controlling method for e.g. amber-colored container, involves calculating coating`s thickness by using specific relationship and detecting theroritical thickness`s coating

摘要

The method involves measuring an intensity transmitted through a sample e.g. amber-colored polyethylene terephthalate container, for two wavelengths chosen in ultraviolet and visible regions, and in an infrared region, respectively. Transmission coefficients are detected at the wavelengths. A dimension i.e. thickness, relative to an amorphous carbon coating/barrier layer is calculated by using specific relationship of transmission co-efficients, a control point and a constant coefficient. A theoretical thickness of the coating is detected at the control point by a linear correlation function.