Archimedes Test Fixture

Used to measure the density of objects via Archimedes' principle in general accordance with ASTM B962/ASTM B311 for measuring density via the Archimedes method.

The setup consists of a stand that straddles a scale, a base plate to hold the vertical arms, and a top plate. Can be printed with PLA for use with water, or with PETG for ethanol or other solvents. In addition to these files, string/ metal wire is needed as well as a beaker and a high-accuracy scale. Designed for a scale with a 127 mm square measuring plate. Tweezers can be used to place samples on the bottom stand.

To take a measurement, the scale is zeroed with no samples on it. Then, samples are placed on the top plate. Here, their weight in air is calculated. After measuring in air, the samples are placed on the plate hanging in the liquid and measured again, which is used to find the volume. Using the displaced volume and the sample's initial weight in air, the density can be calculated. Using a known reference density