How are visual smoke detectors activated in some aircraft?

Visual smoke detectors in aircraft are typically activated by drawing smoke through a line into the indicator. This method relies on the physical movement of smoke from the surrounding area into the detection system, allowing it to assess the presence of smoke and subsequently trigger a visual alert. The design often incorporates an intake system that captures the smoke and directs it toward the detector mechanism, which then interprets the presence of smoke as a condition needing attention.

This approach allows for a real-time and responsive indicator of smoke presence, ensuring that potential hazards are identified quickly, enhancing safety protocols within the aircraft. Other activation methods mentioned, such as external smoke detection systems or manual activation, do not align with the operational mechanism of visual smoke detectors, which are typically automated and rely on the physical properties of smoke rather than manual intervention or external systems. Temperature-sensitive triggers also serve a different function, primarily related to fire detection rather than specifically smoke detection.