Closed-Loop Tuning of Controllers ◾  103
(temperature) rises to its first peak in 15 min. The proportional band is 15%, the integral time is 45 min, and
the derivative is zero. What is the next recommended
step in tuning the control loop in automatic output
mode?
References
1. Ziegler, J. G., and Nichols, N. B., Optimum settings for automatic controllers, Trans. ASME, 64, 759, November 1942.
2. Robbins, L. A., Tune control loops for minimum variability,

CEP, January 2002.

3. Robbins, L. A., Setpoint tuning method gives excellent response
to load changes, Hydrocarbon Proc., September 2002.