ABSTRACT
Probably the first thing one wants to know about a filter medium meant to clarify a liquid is the relationship between the flow rate of particle-free liquid and the driving pressure. Sometimes the supplier of the medium offers this information. Sometimes one must determine it in order to know what the area of the filter medium should be for the volumetric-flow rate of the stream to be clarified. When the filter medium is a flat sheet, one of the simplest setups to take these measurements involves mounting a small-diameter disk of the medium under a column of clear water and measuring the flow rate. Relate the height of the column to driving pressure.
