Which control method is characterized by maintaining temperature with minimal fluctuation around the setpoint?

The control method characterized by maintaining temperature with minimal fluctuation around the setpoint is PI control. Proportional-Integral (PI) control uses both proportional and integral actions to minimize steady-state errors and improve stability. The proportional component helps to reduce the error between the desired setpoint and the actual temperature, while the integral component addresses any accumulated errors over time. This combination effectively dampens oscillations and allows for a smoother approach to the setpoint, leading to reduced fluctuation around that setpoint.

In contrast, other control methods such as On/Off control can lead to significant temperature fluctuations, as they switch fully on or off without regulating the output smoothly. P control, which relies solely on proportional response, may not adequately eliminate steady-state error, causing persistent deviations from the setpoint. PID control, while it also minimizes fluctuations and can provide better performance, introduces a derivative component that is not necessary for controlling steady-state temperature precision and might be more complex than required for some applications. Therefore, PI control strikes a balanced approach, offering stability and minimal fluctuation around the setpoint effectively and efficiently.