Requirements (Instruments, Chemicals & Other):
● Andreasen pipette apparatus
● Weighing balance
● Fine powder sample
● Distilled water
● Measuring flask
● Spatula
● Stopwatch
● Oven
● Collection pans or discs

Procedure:
● Accurately weigh a known mass of the powder sample and transfer it into a clean measuring flask.
● Add a measured volume of distilled water and shake well to obtain a uniform suspension.
● Insert the Andreasen pipette so that its sampling tip is positioned at a fixed depth below the liquid surface. Start the stopwatch immediately after mixing stops to begin timing sedimentation.
● At fixed time intervals (e.g., 0.5, 1, 2, 4, 8 minutes), withdraw samples using the pipette and transfer each to a pre-weighed collection pan.
● Place the samples in an oven to remove moisture completely.
● Weigh each dried sample to determine the mass of solids remaining in suspension at each time point.
● Using Stokes’ law, calculate the particle size corresponding to each sampling time. Plot a graph of cumulative percentage of particles finer than each size versus particle diameter to obtain the particle size distribution curve.