Which device in a dry-type system is known to generate a supervisory signal at the Fire Alarm Control Panel?

• A. Heat detector
• B. Air pressure switch in a dry-type system
• C. Smoke detector
• D. Manual pull station

Answer: (B)

In a dry-type (dry-pipe) sprinkler system, the pipes are filled with pressurized air to keep water out until the system is activated. The air pressure switch monitors that air pressure and sends a supervisory signal to the Fire Alarm Control Panel if the pressure drops below the set point. This alerts you to a potential air supply problem or leak in the dry-pipe system before water could be released. The other devices—heat detectors, smoke detectors, and manual pull stations—trigger alarms when they sense heat, smoke, or manual action, not supervisory conditions.