抄録
There are various methods in measuring the grain size distribution. Manufactured for trial by the authors are two kinds of new apparatus which, based on the principle of centrifugal sedimentation, can measure the grain size by continuously recording the sedimentation process by means of light transmission. One of them is called a D. C. type in which the light receiver rotates together with the sedimentation cell and the other A. C. type in which the light receiver receives pulse-form light instead of rotating. Size distribution of grains of some photographic emulsions which are approximately 0.1-1.0μ in average diameter was measured by these apparatus. Satisfactory coincidence was obtained between the results by centrifugal method and electron microscope method regardless of different grain forms, spherical and tabular.
