Sedimentation is a phenomenon where suspended material settles out of the fluid by gravity. The suspended material can be particles such as clay or powder. The sedimentation process depends on the size, shape, charge and type of the particle as well as the liquid properties. A round particle is known to settle more rapidly than a particle with an irregular shape. If the particles have the same electrical charge, they repel each other which keep them from settling. The lower the temperature of the liquid is, the slower the sedimentation process becomes.
Attension Sigma 700/701 force tensiometers can be used to evaluate the amount of sedimentation of a suspension due to gravity. The suspension liquid is kept still and the balance of the tensiometer measures the mass change of the sedimentation probe within a time period. The higher the mass change is, the faster the sedimentation process occurs. The evaluation of sedimentation is especially important in food and drug industries, where powders need to be characterized in order to know their behavior when coming into contact with liquids. Sedimentation is also relevant in the process of water purification.
Video of a sedimentation measurement using the Sigma 700/701 Force tensiometer: