METHOD OF CHECKING TRANSPARENCY OF FLAT LIGHT-TRANSLUCENT MATERIALS Russian patent published in 1995 - IPC

FIELD: measurement technology. SUBSTANCE: material tested is illuminated by two identical parallel light beams at normal to its surface during material transportation under production. Flat white non-transparent substrate is disposed under one illuminated parts at the side being opposite to the material. Black substrate is disposed under the other part. Light fluxes φ_w and φ_o, are indicated which are dissipated by one and other parts of material at opposite direction in identical small solid angles Ω oriented at identical angles v to each incident beam. Transparency of the material is judged from dc = φ_o,э/φ_w,э-φ_o/φ_w, where φ_w,э and φ_o,э are light fluxes measured by the same method for standard sample of the same material with known transparency. EFFECT: improved precision of measurement. 6 dwg