Soil texture are the medium-sized (0.05 - 0.002 mm) and sink to the bottom of the cylinder after the sand. Clay particles are the smallest (<0.002 mm) and separate out above the silt layer. Measurements are taken using a soil hydrometer. A soil hydrometer measures that relative density of liquids (density of a liquid to the density of water). The hydrometer is lowered into the cylinder containing the soil mixture at different times, forty-five seconds to measure sand content, one and a half hours to measure silt content and between six and twenty-four hours (depending on the protocol used) to measure clay.
Granular material behaviors when excited (e.g. vibrated or allowed to flow). As such granular materials under excitation can be thought of as an example of a complex system. When the average energy of the individual grains is low and the grains are fairly stationary relative to each other, the granular material acts like a solid. In general, stress in a granular solid is not distributed uniformly but is conducted away along so-called force chains which are networks of grains resting on one another. Between these chains are regions of low stress whose grains are shielded for the effects of the grains above