West Control Solutions Pro-EC44 - Manual (Page 89)

Pro-EC44 2-Loop Graphical Profile Controller & Recorder
Pro-EC44 Product Manual - 59540-1 October 2013 Page 82
attempts to make the physical ratio 10. With a setpoint of 1.03 it would attempt to make the
ratio 10.3 for 3% excess air.
The instantaneous (controlled) process value is calculated from the physical ratio, divided by
SFac. Like the setpoint, this is displayed as relative value.
E.g. if SFac is 10, with 59.5m
3
/h airflow measured at x1, 0.5m
3
/h atomising air applied at NO
and 6m
3
/h fuel is measured at x2, the instantaneous process value would be:
If fuel flow remained at 6m
3
/h and the setpoint was adjusted to 1.05 (5% excess air), the
controller would increase the x1 air flow to 62.5m
3
/h.
Typical Ration display with Setpoint at 1.05