Photoelectric detectors are typically used in which setting?

• A. Small Offices
• B. Large Common Areas
• C. Corridors
• D. Exteriors

Answer: (B)

Photoelectric detectors are most responsive to smoldering, smoky fires, because they work by using a light source and a sensor to detect smoke particles that scatter the light. Large common areas are ideal for this type of detector because smoke from a smoldering fire can fill a big open space and take longer to reach a detector, giving the sensor ample opportunity to notice the smoke and trigger an alarm. This makes photoelectric detectors a good match for open, high-occupancy indoor areas where smoke may accumulate quietly before flames become visible. In contrast, exteriors aren’t enclosed spaces where smoke would concentrate to trigger the detector, and corridors or small rooms can have air movement and other factors that aren’t as favorable for this smoke-detection approach.