What are PMI Pycnometers?
Pycnometers are capable of measuring densities of materials. The true density, as well as the bulk density, are accurately measured. True density is computed from the weight and the volume of solids in the sample. The volume of solids is calculated from the loss of pressure of a known amount of gas in the sample chamber when the sample is removed from the chamber. The bulk density is computed from the weight and bulk volume of the sample. The bulk volume is calculated from the decrease in volume of mercury that the sample chamber can contain in the presence of a sample in the sample chamber. Various models of pycnometers may have multiple sample chambers, the ability to work with a number of gases, and/or greater accuracy.