Sampling Method
There is a hole in both of the sedimentation tanks located at the same level as the effluent launderer, from which it is possible to run a small tube to a turbidity meter through a pump. The turbidity is displayed in NTU and can be recorded through process controller in a Microsoft Excel file. (See "Upon Opening Process Controller" on the pilot plant computer's desktop for more information on recording data.) This provides a continuous measurement.
One may test one tank at a time; because the conditions of the incoming water should not be changing significantly, it is assumed that this time delay from one tank's measurements to the next tank's measurements is not significant. However, it is possible to test both tanks simlutaneously by running a pipe through another pump to one of the flocculation tank turbidimeters. (As long as one team is not currently running experiments, the other team can check with the first and use their equipment--just be sure to replace everything properly.)
The turbidity meter needs to be cleaned out before any measurements are taken though, since flocs tend to build up in the small testing unit. If left uncleaned, the turbidity will be far too high, and will not reflect the current state of the tanks.