Hello,
Currently I control a bacterial culture process with DF a LabJack and a Me-UBre relay box. One phase of this process is called the "anaerobic phase".
The pO2 (dissolved oxygen) should be kept at 0 for 2.5 hours. To maintain this value at 0 I open a 12V solenoid valve with a relay at t0 with a fixed
nitrogen flow and I close this valve after 2.5 hours. The gas flow cannot be regulated automatically and the valve is either fully open or fully closed.
In order to save nitrogen, I would like the valve to close when the pO2 is at 0 and that it opens if the pO2 goes back to 0.3 and then closes again when
the measurement is at 0. I would like to use a PID for that. I know that PID is more for fine regulation, but is it possible to use it in this case?
If it is possible I cannot find the settings which allow me this regulation. I have configured a PID, it works very well to lower the pO2 to 0.
Once at 0 the valve closes well, but if the pO2 goes up the nitrogen valve does not open.
The pO2 should not exceed 0.3.
Can you help me?