What conditions trigger an alarm in Cloud Chamber Smoke detection?

The condition that triggers an alarm in a Cloud Chamber Smoke detection system is the presence of smoke particles. This type of smoke detector operates based on the principle of light scattering, where light is emitted into a chamber filled with air. When smoke particles enter this chamber, they disrupt the path of the light by scattering it. This disruption indicates the presence of smoke and triggers the alarm system.

The other options, while relevant to fire detection in general, do not specifically apply to Cloud Chamber Smoke detection. For instance, an increase in temperature might activate heat detectors, and a sudden change in pressure could relate to other types of detection systems. The activation of a manual pull station is a completely different mechanism and does not involve smoke detection but rather relies on human action to alert the system. Thus, the accurate identification of smoke particles as the trigger for an alarm in this type of detector is essential for understanding its functionality.