GRAIN DESCRIPTION BY A RANDOMLY INHOMOGENEOUS OPTICAL MEDIUM MODEL FOR THE INTERLABORATORY MATCHING OF VITREOUSNESS MEASUREMENTS

Currently, due to the appearance of instrumental objective methods for determining grain vitreousness, it is possible to ensure the uniformity of measurements of this indicator in a number of laboratories. The article proposes a model for describing grain as an inhomogeneous optical medium and an interpretation of the vitreousness index as a characteristic of light scattering. A method for calculating the parameters of mathematical model and estimating the scattering coefficient using an RGB camera is presented. It is shown that the implementation of the grain vitreousness measurements based on the scattering coefficient makes possible to obtain a satisfactory reproducibility in between-lab measurements.