What is the primary function of a smoke detector activated in an elevator lobby?

The primary function of a smoke detector activated in an elevator lobby is to notify fire safety personnel. When smoke is detected in an elevator lobby, it serves as an alert mechanism that signals an immediate response to a potential fire situation. This notification system is crucial for ensuring that the fire safety personnel can assess the situation and take appropriate actions to ensure safety, including evacuation procedures and firefighting efforts if necessary.

While it might seem that stopping elevators could be a desired response in the event of a fire, the main purpose of the smoke detector is to communicate the presence of smoke and initiate an emergency response. It's essential for elevator systems to be integrated into the overall fire alarm system, as they may include features such as recalling elevators to a designated floor or preventing them from operating until the danger is resolved, but this response is secondary to the immediate alerting function of the smoke detector.