The density of bulk solids particles is the density of the powders including the space between the particles.
There are two types of density:
- Untapped density or aerated density: this is the density measurement without the powder being compacted
- Tapped density: this is the density measurement with the powder compacted
Therefore, the density of the same granulated material, measured with a densimeter, can vary depending on whether it is more or less compacted.