Which type of continuous control requires elements like meters, transmitters, and transducers?

• A. Proportional control
• B. Feedback control
• C. Open-loop control
• D. Floating control

Answer: (B)

Feedback control involves the use of meters, transmitters, and transducers to monitor and adjust the system continuously. This type of control system uses the output data, which is measured and transmitted back to the controller. The controller then compares the actual output to the desired setpoint and makes adjustments as necessary to minimize the error. This process of constant monitoring and adjustment requires various instrumentation to accurately measure parameters such as flow, pressure, temperature, or chemical concentration.

In contrast, other types of control methods may not rely on direct feedback or do not integrate measurement devices to the same extent. For example, open-loop control operates without using feedback to adjust the process, while proportional and floating control have different mechanisms of adjustment that may not explicitly require continuous monitoring through such instrumentation. Thus, feedback control is characterized by its reliance on real-time data to maintain system stability, making it essential for processes that demand high precision and responsiveness.