Start with the question, then choose the sensor
Start with what your team needs to know: whether a unit door is open, whether someone moved inside, or whether there is movement along a corridor. Door contacts and PIRs answer different questions, so choose their placement around those areas.
| Control or service | What it does |
|---|---|
| Door contact | Reports the monitored door’s open or closed state. Useful for unexpected openings and doors left open. |
| PIR sensor | Detects movement within its coverage by sensing changes in infrared energy. PIRs can monitor inside or outside units, including customer routes. |
Movement does not always begin at the door
If someone enters through a neighbouring partition, the unit door may stay closed. A contact on that door would have no opening to report. A PIR may detect the movement if it falls within the sensor’s coverage. That is why an opening sensor and a movement sensor can usefully protect the same unit.
Contents can change the view
A unit that is empty today may be filled with furniture tomorrow. Items can obstruct a sensor’s view. Placement, detection range and the layout of the stored contents need consideration. Check performance against the intended coverage instead of assuming one sensor observes the entire unit.
The same movement can mean different things
Movement while a customer uses their unit is expected. Movement in an armed area needs investigation. Bearbox links alarm areas with customer visits, temporarily disarming the relevant route and unit while other areas stay protected. Review the visit-end settings so those areas return to protection when the visit finishes.
Useful monitoring also covers ordinary mistakes
A customer finishes unloading and forgets to close the door. A door contact gives your team a different kind of useful information: the unit is still open. A left-open alert can prompt a check or customer contact. That event needs a different response from an unexpected opening in an armed unit.
Notice when a sensor is disturbed
Tamper monitoring can report wiring faults and enclosure openings on supported installed equipment. Treat those events separately from a door opening or movement alarm: the equipment providing protection may need checking. Include tamper notifications in the same response plan as your other site alarms.
Check the information reaches someone
Test that a sensor event reaches the system and the person responsible for investigating it. That person should be able to find the affected unit or area and check the visit records and relevant cameras. A movement alarm tells them where to look; it does not identify the person who moved.