What must be reduced if a controlled variable oscillates about the set point at high frequency in automatic boiler controls?

In automatic boiler controls, if a controlled variable is oscillating about the set point at high frequency, it indicates that the system is overly responsive to changes in the controlled variable. To address this issue, reducing the controller sensitivity is necessary.

Controller sensitivity refers to how responsive the control system is to deviations from the set point. When sensitivity is too high, even minor fluctuations can trigger adjustments, leading to a rapid cycle of corrections that result in oscillation. By lowering the controller sensitivity, these minor deviations do not provoke immediate reactions, allowing for a more stable control process that settles the system around the set point rather than causing it to swing erratically.

This approach stabilizes the control system, preventing high-frequency oscillations and ensuring smoother operation within desired parameters.