What can cause a Passive Infrared Sensor (PIR) to experience a loss of range?

In the context of a Passive Infrared Sensor (PIR), a loss of range can occur due to various environmental factors. When evaluating the factors that impact a PIR's performance, background temperature plays a significant role. If the background temperature is between 84°F and 100°F, the sensor may become less effective. This occurs because PIRs detect changes in infrared radiation emitted by objects in their field of view compared to the background temperature. When the background temperature is too close to the temperature of the objects being detected (such as humans or animals), the sensor might struggle to differentiate between the two, leading to a diminished detection range.

In contrast, physical obstructions or improper installation can affect the sensor's ability to detect motion but do not specifically relate to the thermal detection capabilities that affect range as background temperature does. High humidity, while it can affect electronic devices, does not typically impact the functioning of PIRs in the same critical way as temperature does. Understanding these factors is key to effectively utilizing PIR sensors in various environments.