Settling tube pan and microbalance

After releasing sediment into the top of a settling tube filled with water, a pan and microbalance collects and weighs the sediment as it slowly reaches the bottom of the tube. A computer records the cumulative sediment weight over time, as well as how long it took each particle to reach the pan. Based on standard settling velocities of particle sizes, the 2-meter tubes can report settling velocities in quarter-phi fractions from -1 phi to 4 phi (2 millimeters to 63 microns).