This Botswana Standard specifies a method for determining the proportions of particles of diameter not exceeding 20 μm and not exceeding 5 μm and smaller, in fine aggregate. Particles of different sizes in fine aggregate are divided indirect, by means of sedimentation. The relation between the diameter and settling velocity of spherical particles in water is given by Stokes’ Law. Samples are taken by means of pipette from an aqueous solution in which the material of known density is suspended at a given depth. After a specified standing time, and when the particles are dried and weighed, the proportions of particles of diameter not exceeding 20 μm and of diameter not exceeding 5 μm and smaller, respectively, are determined.