PH Loop
PH control is a difficult problem due to the highly non-linear nature of the system. The steep slope of the titration curve around the pH = 7 point amplifies pH variations for even small base/acid addition variations. The pH control rig in the PMC lab illustrates that pH control is by no means impossible (albeit on a laboratory scale).
Contents
Current/Previous projects
1999
F.J. Botha, Ondersoek van die Dinamiese Gedrag van Sisteme waar pH Gemeet en Beheer word {Investigation of the Dynamic Behaviour of Systems where pH is Measured and Controlled}
[Hard copy of report available in pH rig folder]
2003
T. Leeuw & G. Mascini, pH Rig 2003 - CPL780 Process Control Laboratory
Report | Project files
2005
A.J. Swanepoel & M. Swanepoel (Botha), Model Based Control Laboratory, pH Control
Report | Project files
2007
C. Steyn, Fuzzy Logic Rule-Based Controller Design, Neutralization of Strong Acid with Strong Base
Report | Project files
2009 (Current)
A.H. Campher, Maintenance, Modelling and Control of the pH-control Rig
Report | Project files
Documentation
Large scale renaming of instruments, valves and tanks is being done. This renders all previous rig diagrams obsolete. Only 2009-updated diagrams should henceforth be used.
Piping & Instrumentation diagrams
Wiring diagrams
Rig maintenance
The maintenance of the pH rig is documented here.
