Abstract
Particle size is one of the most important factors to determine soil structure. In this paper, mea-suring of particle size of soil by using Soft X-ray Digi-tal Radiography （SXDR） was examined. Soft X-ray im-age of glass beads and sand of some kinds of particle size were taken, and analyzed by statistical methods. Arithmetic mean, median,standard deviation and coef-ficient of variation of gray levels of pixels in the im-agewere calculated. As a result, it was observed that d, particle size of samples, affectedσgl, standard deviation of gray levels of pixels in the image. Theσgl increased with increasing the d. In addition, correlation between the d and theσgl was aff ected by the number of pixels which was used to calculateσgl. This fact provides us measuring of particle size of soil by using SXDR. To measure of particle size by using the method, sufficient size of image was demanded.
