Hydrometer Method Improved for Making Particle Size Analyses of Soils1

Synopsis The time required for dispersing soils for the hydrometer method of making particle size analyses was reduced from 25 minutes to only 2 minutes. The procedure consists of soaking the soils in a 5% Calgon solution for 15 to 20 hours and then dispersing them with a soil mixer running at a speed of about 16,000 r.p.m., for 2 minutes.