Which of the following best describes the role of a sensor?

The role of a sensor is primarily to detect and measure physical phenomena. Sensors play a crucial part in instrumentation and process control by capturing real-time data from the environment or processes, such as temperature, pressure, flow, or level. This information is essential for monitoring and controlling industrial processes, ensuring that systems operate within desired parameters.

When a sensor detects a physical change, it translates that change into a readable signal, which can then be used for further analysis, output, or to inform control systems. This ability to provide accurate and timely measurements of various variables enables operators to make informed decisions to improve efficiency, safety, and reliability in plant operations.

The other choices describe functions that do not encompass the primary purpose of a sensor. For example, converting electrical signals into physical motion pertains more to actuators, while amplifying control signals is typically the role of signal conditioning equipment. Stabilizing process conditions is generally achieved through control systems that utilize the data provided by sensors to regulate the system appropriately.