colored balls

Laboratory Analysis

Making Sense of Particle-Size Distribution (continued)

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Index Index
bulletHeavy, large particles settle first, so when a soil sample is stirred or shaken in a 500 mL cylinder, sand particles (according to the USDA definition) settle to the bottom of the cylinder after 2 minutes, while the clay and silt size particles stay in suspension.
Clock reading 10:05

Sample Starting Time

Clock reading 10:07
bulletAfter 12 minutes, the sand, according to the ISSS definition, has settled, leaving the clay and silt size particles in suspension.

Clock reading 10:17

bulletAfter 24 hours, the silt size particles have settled, and only the clay stays in suspension to be recorded by the hydrometer.

Clock reading 10:05

The Next Day

Soil Particles Dispersed in Beaker

Particles separated in beaker

Here are the calculation worksheet and the specific gravity conversion table to help figure out the exact percentages of sand, silt, and clay. And here is a draft of the new calculation worksheet.

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