When is a controller in automatic not able to do anything to reduce an oscillation? When will a controller amplify an oscillation? In both of these cases, the controller is doing more harm than good by wearing out valves and upsetting other loops.
Sensor lags, transmitter damping, and PID signal filters can make oscillations look better but is this really a good a thing? Here we look at how these dynamics affect what you see and how much of a problem it can be.
A transmitter damping setting or signal filter setting that is too slow can not only degrade performance but also cause trips. Less understood is that a large filter setting can mislead operations into thinking the filter has helped rather than hurt the process.