What fire protection system uses smoke detectors for early warning of fire?

The automatic smoke detection system is designed specifically to identify the presence of smoke in an environment, which is typically one of the earliest signs of a fire. These systems utilize smoke detectors that are strategically placed throughout a building to provide timely alerts when smoke is detected. The early warning allows occupants to evacuate safely and can trigger alarms and other fire protection measures, significantly reducing potential damage and improving safety.

In comparison, the other systems listed serve different primary functions. An automatic fire extinguishing system focuses on actively suppressing a fire once it has started rather than providing an early warning. The automatic water mist system utilizes fine water sprays to cool and suppress fires but does not primarily rely on smoke detection for its operation. Similarly, the automatic sprinkler system is designed to control or extinguish fires by spraying water when a set temperature is reached, instead of detecting smoke as an initial warning mechanism.

Thus, the automatic smoke detection system is distinctly focused on the early detection of smoke and fire, making it the appropriate choice for this question.