A projected beam smoke detector is an example of which type of detector?

A projected beam smoke detector is an example of which type of detector?

• A. Ionization detector
• B. Photoelectric smoke detector
• C. Heat detector
• D. Line-type device

Answer: (D)

A projected beam smoke detector is a line-type detector because it monitors smoke along a straight path between a transmitter and a receiver. The beam crosses the space, and when smoke enters that line, light is scattered and the receiver detects the change, triggering an alarm. This line-of-sight approach distinguishes it from detectors that sense smoke at a single spot (spot-type photoelectric detectors) or from other types like ionization detectors (which sense flame chemistry) and heat detectors (which respond to high temperatures). The defining idea is that the detector covers a line across the room, not just a single point.

A projected beam smoke detector is a line-type detector because it monitors smoke along a straight path between a transmitter and a receiver. The beam crosses the space, and when smoke enters that line, light is scattered and the receiver detects the change, triggering an alarm. This line-of-sight approach distinguishes it from detectors that sense smoke at a single spot (spot-type photoelectric detectors) or from other types like ionization detectors (which sense flame chemistry) and heat detectors (which respond to high temperatures). The defining idea is that the detector covers a line across the room, not just a single point.