What is the primary purpose of a smoke detector?

The primary purpose of a smoke detector is to detect smoke as an indication of fire. Smoke detectors are designed to respond to the presence of smoke particles in the air, which is one of the earliest signs of a fire. By detecting smoke, these devices can provide critical alerts to occupants, allowing them to evacuate safely and seek assistance before the situation escalates.

While other options relate to important safety functions—like monitoring temperature changes or carbon monoxide levels, and alerting emergency services—these are not the main function of a smoke detector. Smoke detectors focus specifically on identifying smoke to warn individuals of potential fire hazards, making this their essential and distinguishing purpose.