Other than beam, what is another way to trip a photo-electric smoke detector?

A photo-electric smoke detector functions by using a light source, typically a laser or LED, and a light sensor positioned in a detection chamber. When smoke enters this chamber, it interferes with the light path, triggering the alarm. One alternative method to activate this type of smoke detector is reflective light, which can cause the light to bounce back into the sensor without the need for smoke. Movement can also create disturbances in this light path, inducing the sensor to react.

This makes reflective light or movement a valid method to trip the detector as it alters the normal operational state. High temperature may not specifically trigger this type of detector since it relies on smoke to interfere with the light. Direct contact, while it could potentially affect components of the smoke detector, is not a standard or reliable method for tripping it. Sound waves do not interact with the light sensor mechanisms in a way that would activate the alarm in a photo-electric smoke detector.