MET 382 Deadband and Hysteresis

[@abdullahalsulieman2096]

Great Job. Can a dead band be an indication of a process control degradation? For example, if I am trying to monitor the performance of a pressure control loop on a separator, and I look at the oscillation or the pressure behavior over time. And I noticed that the time to stabilize the pressure to the set point is trending up or that the pressure never is at the set point due to dead band phenomenon, Can I conclude that the pressure control loop is starting to degrade?

[@damonsisk4270]

Regardless whether deadband is the culprit or not, the change you describe is definitely degradation of control. How well a control loop performs can be characterized 5 main considerations: 1) minimum error at steady state 2) want to minimize amplitude of oscillations 3) time to reach setpoint 4) overshoot ,and 5) stability. What you have described sounds like a decrease in stability of control (5) or increased time to reach setpoint (3), so your process control quality has decreased.

[@abdullahalsulieman2096]

@@damonsisk4270 Thank you so much. Very informative.