OK, so here’s a shameless plug for my short book “Mastering Split-Range Control”. It’s 30 pages, with everything you could ever want to know about Split-Range Control. Available via Amazon CreateSpace at: https://www.createspace.com/3395995 .

Split-range control uses a single controller with two control valves to maintain a single process variable. It can be used for a variety of applications, such as heating and cooling of a tank or a room. Split-range control is widely used in the process industries, such as pulp and paper, oil and petrochemicals, and mining.

The book covers all aspects of the use of split-range control. Starting with the basics, the book discusses when to use split-range and when not to, costs and benefits, how to configure the control strategy, how to calibrate the valves, how to tune the loops, and even how to train operators and troubleshoot problems. Color pictures illustrate the key concepts.


Ah, summer! Time for days at the beach, relaxing with family. Take some downtime around the house, order take-out food, and let teh laundry go for a few days. It feels to good that we don’t have to be “in control” all the time.

But what about your plant? Can you afford for it to not be “in control”?

It may surprise you to find out that, in a typical plant, 30% of control loops are running in MANUAL. That is, they are not “in control” at all. Any upset that comes along passes right through!

This can lead to losses in efficiency, and greater potential for safety or environmental problems. In fact, control loops left in manual have been found at the root cause of several industrial disasters.

Should you run out to the plant, and force everything into AUTO? No, no, no!! Control Loops in MANUAL are more of a symptom than a problem. Usually, the operator put the loop in MANUAL for a reason: The tuning was bad, the instrument failed, or there was a control valve problem.

As a good control guru, you want to be sure that your plant stays “in control”, even while you are out on vacation. Here are some suggestions:
1. Start by understanding the extent of the problem in your plant. Monitor the % of control loops in MANUAL using on-line tools, like Control Loop Monitoring.
2. For each loop, make sure you understand WHY it was left in MANUAL. Ask the operators. Then resolve the root cause issue.
3. Continue to monitor for loops in MANUAL. This is a very effective way to spot new problems when they occur, even if the operator forgot to tell you about it.

Want to become a better process control guru? How about taking a course at MIT…without leaving the comfort of your own home!  For free!!

I’m not kidding: The Massachusetts Institute of Technology (MIT) has put quite a bit of course material online, including these:

  • Control of Manufacturing Processes
  • Modeling Dynamics and Control
  • Dynamics and Control
  • Introduction to Robotics
  • Mechatronics

You can see videos, download course materials, and hear podcast lectures.  There is NO CHARGE for this service.  However, you can make a voluntary contribution to MIT  if you find the information valuable.

Here’s the link: MIT’s On-Line Courseware
Check the Mechanical Engineering section first…many controls courses are listed there.

I highly recommend that you try some of these courses.  If you find them worthwhile, please consider a contribution.  This type of high-quality on-line material is exactly what we need, to hone our skills and become better process control gurus.

Times change. The business climate changes, from week-to-week, month-to-month, and year-to-year. As a process control engineer, what should you do differently, in different business climates?

In the current economic recession, many businesses are experiencing “soft demand”. In other words, they can’t sell everything they make. In many plants, this leads to a slow down or partial shutdown.

In this business climate, it is often more important to be the “low cost producer” of products.

What can you do to help? Here are some ideas:

1. Pay attention to costs. Energy costs, in particular, can often be reduced through better control tuning and control strategies.

2. Find out how to help the plant transition between production rates or between products. In many plants, there is a great deal of waste during these transitions.

3. Work on projects to improve yield and efficiency. If you need money for these projects, be ready to explain the cost and the benefits in economic terms.

4. Use downtime to accomplish small improvement projects and to train others.

5. Update your resume. Always have a “plan B”. If there is a downsizing or plant closing, you want to be ready for it.

These should help you and your business to weather the storm. Remember to pay close attention…the business climate will changes again.