Which of the following is NOT a function of a public address system in a fire emergency?

The role of a public address system during a fire emergency is primarily focused on communication. It enhances safety by clearly giving instructions to occupants, which is crucial for guiding them during an evacuation. This system is designed to communicate effectively within buildings, including terminating in stairways and lobbies to ensure that messages can reach everyone, regardless of where they may be located in the building.

Providing communication on individual floors allows for tailored instructions, addressing the specific needs of people in different areas of the building during an emergency. Given these functions, the notion that a public address system would automatically detect smoke is inaccurate. Smoke detection is typically the responsibility of dedicated fire alarm systems, rather than a public address system, which is meant for communication purposes.