In control systems, what is the primary purpose of a sensor?

The primary purpose of a sensor in control systems is to detect changes in a variable. Sensors play a crucial role in monitoring environmental conditions or system variables such as temperature, pressure, flow, and level. They convert physical phenomena into electrical signals that can be read and interpreted by control systems or operators.

By measuring these variables, sensors provide real-time data that enables the system to respond appropriately to changes. For instance, if the temperature surpasses a set threshold, the sensor detects this change and sends a signal to the control system, which can then execute corrective actions, such as activating a cooling mechanism.

This detection capability is fundamental for maintaining system stability, ensuring proper functioning, and facilitating automation. The other provided options, while related to functions within control systems, do not encapsulate the primary role of a sensor as effectively as the detection of variable changes.