Which statement best defines a sensor's role in building automation?

Which statement best defines a sensor's role in building automation?

• A. A device that measures a variable and transmits a signal
• B. A device that stores configuration data
• C. A device that controls actuators directly
• D. A device that provides user input

Answer: (A)

Sensors in building automation are the ears of the system: they measure a physical property and feed that data into the control logic. The statement that a sensor measures a variable and transmits a signal captures this core function—turning a real-world condition (like temperature, humidity, light, or occupancy) into an electrical or digital signal that the controller can use to make decisions. For example, a temperature sensor reads the room temperature and sends a value to the controller, which may then adjust heating or cooling. Storing configuration data belongs to memory or a database, not sensing. Directly controlling actuators is the job of the controller and the actuator, not the sensor. Providing user input relates to human interaction interfaces, not sensing.

Sensors in building automation are the ears of the system: they measure a physical property and feed that data into the control logic. The statement that a sensor measures a variable and transmits a signal captures this core function—turning a real-world condition (like temperature, humidity, light, or occupancy) into an electrical or digital signal that the controller can use to make decisions. For example, a temperature sensor reads the room temperature and sends a value to the controller, which may then adjust heating or cooling. Storing configuration data belongs to memory or a database, not sensing. Directly controlling actuators is the job of the controller and the actuator, not the sensor. Providing user input relates to human interaction interfaces, not sensing.