Which type of smoke detector is typically more sensitive to smoldering fires?

• A. Photoelectric smoke detectors
• B. Ionization smoke detectors
• C. Carbon monoxide detectors
• D. Heat detectors

Answer: (B)

The correct choice is photoelectric smoke detectors, which are designed to be particularly sensitive to smoldering fires. These detectors operate using a light source and a photosensitive sensor. When smoke enters the sensing chamber, it scatters the light, which triggers the alarm. Smoldering fires, such as those caused by materials like upholstery or mattresses, typically produce a lot of smoke before they flare up into open flames, making photoelectric detectors more effective in detecting these types of fires early.

Ionization smoke detectors, while good at detecting fast-flaming fires, are less responsive to slow-burning, smoldering fires as they rely on the ionization of air within the chamber, which can be less affected by the presence of smoke particles from smoldering materials. Carbon monoxide detectors are designed to detect the presence of carbon monoxide gas, not smoke, and heat detectors respond primarily to changes in temperature rather than smoke particles.