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, relative density/porosity can also be evaluated.

Potential errors in the setup can arise from several sources. If liquid is dripped onto the stand, the scale measures the liquid's weight. Additionally, bubbles on the sample surface can increase the buoyant force upon submersion. Bubbles can be reduced by using liquids with low surface tension, such as ethanol. There is also a risk of inaccurate readings due to the stand sliding on the scale. This was used to measure the relative density of laser powder bed fusion metal cubes. After completing this testing, I have several suggested improvements to the setup to reduce errors and improve ergonomics, as measuring with the current setup requires significant dexterity.

Measurements should be easier if the stand were raised and a shorter, wider beaker were used. Double-sided tape could be used to secure the stand to the scale to prevent sliding. A printed basket attached with four supports above would be more stable and prevent tweezers from getting caught up in the wires. To prevent water absorption in a printed basket, it should be saturated with liquid prior to measurement.