When using exterior photoelectric detectors, when should an alarm signal be initiated?

Initiating an alarm signal when a minimum of two detectors on the same vertical plane are activated is critical for enhancing security and reducing false alarms. This method helps ensure that the detected intrusion is legitimate and not caused by non-threatening sources, such as animals or environmental factors. Using two or more detectors provides a more reliable assessment of whether a genuine security breach is occurring, as it indicates that movement is detected across a defined area rather than from a singular source of disturbance.

This approach is particularly important in exterior security systems where the likelihood of false alarms can be higher due to the presence of various external stimuli. By implementing this dual activation requirement, security systems can maintain their integrity and focus on actual threats, ultimately improving response effectiveness.