pH control is an application where everything can be important. A less than right piping, equipment, measurement, control valve, and loop design and implementation can spell big time problems. It is a great training ground and the lessons learned are valuable for many other difficult and important process control applications. The understanding required to make a pH loop work contribute to a much more complete skill base.
I spent a lot of time on pH startups. I found most of the key design concepts needed for success where not discussed anywhere, For example, the normal dip tube design for reagent injection is disastrous and the mixing and valve resolution requirements are exceptional. I discovered how I could reduce the number of stages of neutralization, offer inexpensive alternatives to the classical neutralization vessel, and decide when signal characterization could help or hurt your control objectives.
In an intense ISA Live Web Seminar on May 16 at 2:00 pm EDT, I am summarizing the best of what I have learned. All registration fees go to ISA, which is the technical society most in tune with the automation engineer in the process industry. The link to the seminar registration page is
The seminar is much more cost effective if the registrant connects in a conference room with a computer projector.
This seminar may help you avoid a tough pH startup.
Top Ten Signs of a Rough pH Startup
10. Food is burning in the operators’ kitchen
9. The only loop mode configured is manual
8. An operator puts his fist through the screen
7. You trip over a pile of used pH electrodes
6. The technicians ask: “what is a positioner?”
5. The technicians stick electrodes up your nose
4. The environmental engineer is wearing a mask
3. The plant manager leaves the country
2. Lawyers pull the plugs on the consoles
1. The president is on the phone holding for you