Which factor is NOT a common cause of false alarms in PIR systems?

In the context of Passive Infrared (PIR) systems, false alarms can occur for several reasons, primarily due to the sensitivity of the sensors to environmental changes. High winds, direct sunlight, and the presence of pets can all trigger a PIR sensor, leading to false alarms.

When considering high winds, it is important to note that they can cause movement of objects that might be detected by the PIR sensors, such as trees or loose materials. This movement can simulate the presence of a human or animal heat signature, thereby causing an alarm.

Direct sunlight can also lead to false alarms because the changing temperature of surfaces warmed by the sun can affect the infrared readings of the sensor. These temperature variations can confuse the system into thinking there is motion when, in fact, it is just external lighting conditions affecting the sensor.

While pets are a well-known contributor to false alarms as they can easily move through the detection zone, a space heater is not typically a common cause of false alarms. Space heaters can artificially increase the temperature in a room, but they do not induce movement or change the heat signature in a way that would trigger a PIR sensor as solidly as environmental factors do. Therefore, while it can affect overall temperature, in terms of directly causing a false