Which type of detector is better at sensing smoky fires?

The photoelectric detector is particularly effective at sensing smoky fires because it operates using a light beam and a light sensor to detect changes in the environment. When smoke particles enter the sensing chamber, they scatter the light beam, triggering the alarm. This design makes photoelectric detectors highly sensitive to smoldering fires, which produce a lot of smoke before flames become prominent.

In contrast, ionization detectors are more responsive to fast, flaming fires that produce little smoke, as they rely on changes in ionization levels within a chamber. Projected beam detectors are typically used in large spaces and can cover extensive areas, but their effectiveness depends on the configuration of the beams and their alignment rather than on detecting smoke specifically. Multi-criteria detectors utilize multiple sensing technologies to enhance detection capabilities, but they might not be as specialized for detecting smoke as dedicated photoelectric detectors.

Therefore, for sensing smoky fires, the design and operational principles of the photoelectric detector make it the best choice.