1. Heat sources and temperature changes
PIR sensors respond to changes in infrared energy across the detection zones. Heaters, hot air outlets, equipment surfaces and rapidly changing temperatures can create unwanted triggers or reduce useful contrast. Keep the lens away from strong local heat sources and test under the expected operating conditions.
2. Strong airflow and moving surroundings
Airflow does not directly represent a person, but it can move curtains, packaging or warm objects through the sensor field. Ventilation outlets can also create fast temperature changes. Review both the sensor position and everything that can move nearby.
3. Detection direction and obstructions
PIR detection is generally stronger when a person moves across detection zones rather than directly toward the lens. Doors, shelves, diffusers and enclosure edges can block part of the field. A walk test should cover the real approach direction, not only the center of the room.
4. Mounting height and geometry
Changing mounting height changes the area covered by the sensor. Recessed ceiling sensors also depend on cutout, cavity depth and lens exposure, while wall sensors depend on box position and faceplate orientation. Use the approved model-specific drawing before cutting or drilling.
5. Delay, daylight and final commissioning
A correct physical installation can still feel wrong when delay or daylight settings do not match the space. Commission the sensor with the final lamp or controlled load, then test daytime and low-light behavior, retrigger response and the full occupied route.
Record the accepted settings with the product revision. This gives production and service teams a repeatable reference for future orders.