We shifted the probe around during pilot studies and found that one point near
the inlet of the aerator provided a consistent and representative sample of average
tank conditions. Observations from the left side of Fig. 2 produced erratic measurements,
as saturated turbulent jets emanating from the paddles created eddies
intertwined with oxygen deficient water from upstream. Oxygen readings were more
consistent at points (A, B, C, and D) on the right side of the tank. Only point D
was used for on-going work because it was closer to the aerator intake and assumed
to produce the best mix of tank water after dissipation of turbulence, yet far
enough away to avoid splash effects.