Is there anyone here who has experienced a loop for controlling pH by dosing some chemicals upstream of sample point? In one case the sample point is far away from dosing point and a long sample line is used to bring sample to sensor. I use a PI controller to adjust injection of dosing pump. But it never works and always bouncing.
In my opinion, this is long sample line cause a bad lag in system which can not be removed easily.
In my opinion, this is long sample line cause a bad lag in system which can not be removed easily.