Passive Infrared (PIR) Sensors should avoid being directed at which of the following?

Passive Infrared (PIR) sensors are designed to detect motion by sensing the infrared radiation emitted by objects, particularly living beings. When placed correctly, they can effectively monitor areas for movement by detecting changes in heat signatures.

Pointing PIR sensors at windows can lead to false alarms and degraded performance. This is primarily because windows may allow sunlight or external heat sources to enter, potentially causing significant fluctuations in temperature that the PIR sensor might misinterpret as motion. In contrast, directing the sensors towards rooms, ceilings, or doors typically provides a clearer view of the intended detection zones, helping to minimize interference from external heat sources and enhancing the effectiveness of the alarm system.

By avoiding windows, the reliability of the PIR sensor in detecting genuine intrusions is improved, ensuring better performance of the overall intrusion detection system.