Answer: A. Fine-tuning device.
Answer analysis: When discussing this question, we first need to understand the basic components of an automatic control system. A typical automatic control system is mainly composed of several key parts that work together to achieve automatic control and adjustment of the system. Now, let's analyze each option one by one to determine which one does not belong to the component of an automatic control system.
A. Fine-tuning device: In the standard components of automatic control systems, we do not often see "fine-tuning device" as an independent, standard component. The term fine-tuning device may refer to some kind of adjustment or calibration tool, but it does not directly correspond to the core component in the automatic control system. In an automatic control system, adjustment and calibration are usually achieved through controllers, actuators, and feedback mechanisms, rather than through a separate "fine-tuning device".
B. Actuator: The actuator is a key part of the automatic control system. It is responsible for receiving control signals from the controller and converting them into physical actions to achieve control of the controlled object. For example, in a temperature control system, the actuator may be a heating element or a cooling fan, which adjusts the temperature according to the instructions of the controller.
C. Measurement transmitter: This is also an important part of the automatic control system. The measuring transmitter is responsible for detecting the actual state of the controlled object (such as temperature, pressure, flow, etc.) and converting it into a signal that the controller can understand. In this way, the controller can make decisions based on these signals and send corresponding control signals to the actuator.
D. Controlled object: The controlled object is the core of the automatic control system. It is the entity that needs to be controlled and adjusted. For example, in a temperature control system, the controlled object may be the air in the room; in a motor control system, the controlled object may be the speed of the motor.
In summary, the fine-tuning device is not a standard or core component in the automatic control system. It may be a tool or device under a broader concept, but when discussing the basic components of the automatic control system, we usually do not include the fine-tuning device.
Therefore, the component that does not belong to the automatic control system is A. Fine-tuning device.