A smoke detector functioning on heat and smoke is best described as which type of device?

A smoke detector that operates based on heat and smoke is best described as a detector because its primary function is to identify the presence of smoke or an increase in temperature that indicates a fire. Detectors are specifically designed to sense specific conditions or changes in the environment and trigger an alert or alarm when those conditions are met. In the context of fire safety, smoke detectors serve a crucial role in early warning systems, making them essential devices for preventing fire-related tragedies.

While sensors can measure various environmental parameters, including smoke and heat, the term "detector" more accurately captures the specific function of the device in question—to detect and alert occupants of the presence of smoke or heat indicative of a fire hazard. Other options like receiver and transmitter relate more to communication systems, where information is sent or received, rather than to the specific action of sensing smoke or heat, which is the core purpose of a smoke detector.