Translucency measurement

摘要

The translucency of a material is determined by illuminating an area of the material and detecting the intensity of radiation leaving the material as a function of distance (in a plane parallel to the material) from the radiation source. The resulting measurements may be used to determine a "translucency gradient" for the material. In the case of materials in sheet form or having a defined thickness, the translucency can be measured in transmission mode to measure "through translucency". The device shown, however, is intended for use in back scattering mode to measure "surface translucency" when applied to a test material 11 and comprises a light source 10 coupled to a fibre optic bundle 12 so as to illuminate an area of the material. Scattered light is collected by rod lenses 13 and fed to a detector 14 which is divided into a number of concentric rings. The resulting signal profile of intensity against distance from the illuminated area is analysed by a neural network 22.