Compatibility check 1: PIR field of view
For smart motion sensors, record the exact value, standard, measurement, or supported condition behind PIR field of view before checkout. A broad category label does not prove that the selected variant fits. Confirm the manufacturer, complete model, hardware revision, electrical rating, protocol, controller support, included parts, and region rather than assuming similarly named products share limits.
Compatibility check 2: mount height and direction
Test mount height and direction across the actual fixture, circuit, controller ecosystem, radio path, owner account, and manual fallback—not a product-photo setup. If this smart motion sensors fit depends on a neutral wire, hub, bridge, account, subscription, compatible controller, professional installation, or reliable cloud service, confirm the exact part, service, or behavior as part of compatibility.
Compatibility checks 3 and 4: pet immunity and heat sources; cooldown interval, battery, and hub latency
For smart motion sensors, pet immunity and heat sources and cooldown interval, battery, and hub latency are the limiting conditions most likely to surface only after installation. Measure the smallest clearance, weakest connection, least compatible user or device, and the most demanding normal task. Passing an ideal bench test is not enough.
Prove fit in a reversible order
Use this sequence: place the sensor across the walking path, test day and night, mask unwanted zones, and tune timeout before connecting important automations. Keep labels, packaging, manuals, and the previous system until the product works through normal use and a recovery test. Photograph wiring, measurements, or assembly states that would be difficult to reconstruct.
A failed fit check is a stop signal
Stop when stationary occupancy must be detected, pets or HVAC produce persistent false triggers, or a missed event creates a safety risk. Do not repair a fundamental mismatch with unapproved accessories, copied settings, or community anecdotes. Use presence sensors when it meets the job with a clearer compatibility path.