What triggers the warning light and bell in a smoke detection system?

The warning light and bell in a smoke detection system are triggered by a signal from the smoke detector amplifier. In a smoke detection system, smoke detectors operate by sensing the presence of combustion particles or changes in the environment associated with the development of smoke. When smoke enters the detector, it causes a change in the environment that the detector's sensor can identify.

This change, such as the presence of smoke particles, is processed by the smoke detector amplifier, which then generates a signal indicating that a fire condition has been detected. This signal is what subsequently activates the warning light and the bell, alerting the crew to the potential presence of smoke or fire and prompting immediate action to ensure safety.

In contrast, while an increase in temperature might indicate a fire, it does not specifically trigger the system designed to identify smoke. A manual override would not typically be part of the automatic warning features, and simply activating a smoke particle detector isn’t the direct cause of the alert; it’s the subsequent actions of the amplifier that effectively initiate the warning.