Calibrate the Spec 20 as described above. The program will request the name of a file to which the data collected during the run will be written. Any air in the pump should be washed out. Blue dye will enter the last vessel, and the Spec 20 transmittance will drop. AKP is the proportional gain, AKI is the integral gain, and AKD is the derivative gain.
Smaller gains tend to give sluggish but stable control.
Numbers corresponding to these values will also be printed below the plot. The control algorithm tries to drive the error to zero, corresponding to the green line at the x-axis of the plot. The run will terminate when 300 data points have been collected. The data will be written to the named file at the end of the run. Or, you may want to reset the ball valves to allow the flow to pass through all three vessels, and observe the effect of this change on the quality of the control.