What is the primary function of a photo beam in security systems?

The primary function of a photo beam in security systems is to create an alarm zone. Photo beams consist of a transmitter and a receiver that emit and detect a light beam, usually infrared. When an object or person passes through the beam, it interrupts the light, which triggers an alarm or alerts the security system. This creates a defined area where any movement can be detected, effectively acting as a security perimeter.

The importance of creating an alarm zone lies in its effectiveness for intrusion detection. By establishing these invisible lines, photo beams can cover specific entry points, outdoor perimeters, or areas where unauthorized access is a concern. This capability makes them a crucial component in many alarm systems aimed at protecting property and ensuring the safety of individuals.

Other functions, like detecting motion, can be related but are not the primary role of photo beams. Instead, motion detection is often more associated with passive infrared or microwave sensors. The aspects of resisting corrosion or providing visual surveillance are not relevant to the function of photo beams, as they do not inherently resist environmental factors nor do they offer a visual feed to the user.