Which type of heat detector uses wire or tubing along the ceiling of large open areas?

• A. Fixed Temperature
• B. Spot Detectors
• C. Line Detectors
• D. Photoelectric

Answer: (C)

Line detectors, also called linear heat detectors, are designed to cover large, open spaces by running a heat-sensitive element along the ceiling. As heat from a fire raises the temperature along the line, the system trips wherever the line reaches its activation point, providing broad area coverage with relatively few devices. This makes them ideal for open areas like warehouses or hangars where placing many spot detectors would be impractical. Fixed-temperature heat detectors trigger at a set temperature at a single point, spot detectors are individual units placed in various locations, and photoelectric detectors sense smoke, not heat.