ABSTRACT
A compact solid (e.g., a crystal) has a fairly well-defined "density," in that this term implies the weight of the substance per real volume. Hence, it has the dimension of mass per volume (g/cm\ When dealing with particulates, however, the volume V (of a drum, for instance) is partly occupied by solid particles, and partly by void space. Hence, if the mass M of powder in the drum is determined by weighing, then the ratio:
p' = M/V (16.1)
is a "density term." It is obviously smaller than the "true" density (e.g., of a crystal, or the particles from which the powder is made up), and pi is referred to as apparent density or bulk density.
