Which type of detector uses a light source and a photosensitive sensor?

Which type of detector uses a light source and a photosensitive sensor?

• A. Ionization
• B. Heat
• C. Photoelectric light scattering detectors
• D. Ionization and photoelectric detectors

Answer: (C)

A detector that uses a light source and a photosensitive sensor works by detecting smoke through light interactions. In a photoelectric light scattering detector, a beam of light is emitted into a sensing chamber. When the air is clear, most of the light goes away from the sensor, so nothing triggers the alarm. When smoke enters the chamber, the particles scatter the light, and some of that scattered light is captured by the photosensitive sensor. The sensor detects this change and triggers the alarm. This method relies on light and a sensor, unlike ionization detectors (which depend on ionized air and current) or heat detectors (which respond to temperature). The combination option mixes two different principles, but here the key idea is the light-based, photosensor mechanism of the photoelectric light scattering type.

A detector that uses a light source and a photosensitive sensor works by detecting smoke through light interactions. In a photoelectric light scattering detector, a beam of light is emitted into a sensing chamber. When the air is clear, most of the light goes away from the sensor, so nothing triggers the alarm. When smoke enters the chamber, the particles scatter the light, and some of that scattered light is captured by the photosensitive sensor. The sensor detects this change and triggers the alarm. This method relies on light and a sensor, unlike ionization detectors (which depend on ionized air and current) or heat detectors (which respond to temperature). The combination option mixes two different principles, but here the key idea is the light-based, photosensor mechanism of the photoelectric light scattering type.