Abstract: A compaction device for determining envelope and bulk densities of sample materials. The device uses a rotating sample cylinder and a plunger positioned within the cylinder. The force on the plunger is measured as the plunger advances in the cylinder. The position of the plunger at which a predetermined level of force is applied thereto is determined. Envelope density is determined from the difference in the advance of the plunger when the cylinder is partially filled with a dry flowing medium and when a sample material such as a rigid object is added into the medium. Bulk density is determined from the difference in the advance of the plunger when the cylinder is empty and when the cylinder contains a sample material such as a powder.

Abstract: An apparatus and method for measuring the volume and calculating the envelope density of an object of known weight. The apparatus has a hollow sample cylinder of known interior diameter mounted to a motor for rotation about its horizontal axis. A dry flowing medium is placed in the sample cylinder and a plunger is removably positioned therein. The plunger is mounted to another drive motor for axial movement within the sample cylinder to compact the dry flowing medium. A load cell connected to the plunger measures the force on the plunger as it advances in the sample cylinder. Control means responsive to the load cell determines the position of the plunger in the sample cylinder at which a known force is exerted on the plunger. The control means also calculates the volume of the dry flowing medium in the sample cylinder both with and without the object positioned therein and divides the difference in the volumes into the weight of the object.

Abstract: A gas comparison pycnometer is disclosed which provides a method and apparatus for determining and checking the accuracy of the volume of a solid substance. The pycnometer is also outfitted with a unique cap assembly which fixes the volume in the pycnometer's sample chamber from run to run. The pycnometer also employs a series of purges with a suitable gas to carry unwanted moisture and vapors out of the system. This pycnometer solves many problems in the prior art by quickly and accurately determining the volume of a solid substance.