Definition - What does Hydrometer Analysis mean?
A hydrometer analysis is a measurement method used to determine soil particle size in a sample. Hydrometer analysis is specifically for soil particle sizes that are less than approximately 0.75 mm in diameter. To perform the test, a hydrometer is placed in a container filled with a water and soil mixture and measurements are taken over time.
Corrosionpedia explains Hydrometer Analysis
To perform a hydrometer analysis, several pieces of equipment are needed: a device to mix the soil with a dispersing agent, liquid containers, graduated cylinders and a hydrometer.
The first step when performing a hydrometer analysis is to take the soil sample and mix it into a slurry with the dispersing agent. Then, the slurry is placed into a graduated cylinder and water is added until the combination reaches a specified volume. The water and the slurry are then thoroughly mixed together. Next, a hydrometer is placed into the graduated cylinder. Measurements are taken over time as the soil settles in the graduated cylinder. The time measurements and the hydrometer measurements are then entered into the Stoke's Law equation, which is used to determine the particle sizes.