Pet-Friendly Motion Sensors: Weight Limits Compared

The weight-rating table

All figures below come from the manufacturers' own product pages, support articles, or datasheets, accessed August 2026. Where a maker publishes no figure, the table says so rather than guessing.

Two readings of this table are worth resisting. A higher number is not automatically a better sensor; it is a different tuning of sensitivity, and an 80 lb rated sensor set up wrong will false-alarm on a cat, while a 45 lb rated Bosch mounted per the datasheet may sail through with a 40 lb dog. And Abode's blunt no is arguably the most honest line in this table: every PIR pet rating is probabilistic, and Abode simply declines to promise one.

How passive-infrared pet immunity actually works

A PIR motion sensor does not see shapes. It detects moving heat across a grid of detection zones, and pet immunity is mostly geometry plus signal processing: a 30 lb dog on the floor presents a small warm object low in the field of view, while a person presents a large warm column through many zones. The sensor's firmware discounts small, low signals. DSC describes this as analyzing body dimensions to differentiate pets; Ring's tiers work by simply requiring more movement before triggering.

This is why every manufacturer attaches conditions, and why weight is only a proxy. The failure cases the makers themselves document: a pet that gets close to the sensor looks large (SimpliSafe warns that pets within a few feet can trigger even Gen 2 in Pet Mode), and a pet that climbs furniture, stairs, or cat trees rises into the zones calibrated for human height. Two pets moving together can also sum into a bigger signal, which is why Bosch scopes its rating to one or two pets.

Mounting height is the other half of the contract. SimpliSafe's Gen 1 guidance for larger pets is to mount the sensor about 4 ft up with the test button facing down, so it looks straight out and upward over the pet; Gen 2 with Pet Mode is recommended at 6 ft. Aqara advises 6 to 8 ft, angled downward, for small to medium pets. If you mount a pet-immune sensor at the wrong height or aim it at a staircase, the printed weight rating stops applying, and no manufacturer will honor it as a guarantee.

Model notes, by the datasheet

Honeywell/Resideo IS335: the highest published figure here at 80 lb, selectable (you can turn pet immunity off). It is a wired professional-install sensor with a 40 x 56 ft range, typically installed with traditional alarm panels rather than DIY systems.

SimpliSafe Motion Sensor Gen 2: Pet Mode is a software toggle (app: Device Settings, Motion Sensitivity, Pet Mode) and covers pets under 60 lb. SimpliSafe's false-alarm article adds the honest caveat that smaller dogs and cats can still trigger it at close range. The Gen 1 sensor has no published weight figure; SimpliSafe handles pets on Gen 1 purely through mounting position (roughly 4 ft, inverted, for larger pets).

DSC LC-100-PI: a wired PIR rated for pets up to 55 lb (25 kg), common in professionally installed and older systems. Note that DSC's product page carries a discontinuation notice for its LC-1XX hardwired detector line, so treat this entry as a reference for systems already on the wall rather than a new-purchase pick. DSC also lists dual-technology (PIR plus microwave) detectors with the same 55 lb rating.

Ring Alarm Motion Detector: pet handling is a sensitivity slider, not a dedicated immunity mode. Low sensitivity is designed for multiple or larger pets, 50 lb or less; Medium for one pet or several small pets, 30 lb or less; High is not recommended with pets at all. Ring's support page is unusually candid: the slider adjusts general sensitivity, and there may be no setting at which a particular pet stops setting off the alarm. Ring recommends using Test Motion and the seven-day practice period to find out before real alarms are on the line.

Bosch Blue Line Gen2 (ISC-BPR2-WP12): the pet-friendly model ships with pet immunity on by default and is specified to ignore one or two pets up to 20 kg (45 lb) or numerous rodents. Bosch sells a parallel non-pet model, which matters: with Bosch you choose pet immunity at purchase time, not in an app.

Abode Motion Sensor: Abode's product FAQ states the sensor will detect pet motion and trigger the alarm in Away mode, and points to placement tips rather than claiming immunity. If you run Abode with pets, the practical options are placement, sensitivity adjustment, and excluding pet zones from the sensor's view.

Aqara: no published weight rating on the models we checked. Aqara's placement guidance (6 to 8 ft mounting, angled down, for small to medium pets) is the only official pet-related figure we found. If a hard weight number matters to you, Aqara does not currently give you one.

Practical advice that survives contact with a real pet

Test before you trust. Ring's test mode and practice week, SimpliSafe's sensor test, and Abode's test mode all exist so you can walk the dog through the room, armed in test, before a false dispatch happens. A false alarm with professional monitoring can mean a call, a passcode request, and in some jurisdictions a fine for repeated false dispatches, so the testing step has real money attached; the monitoring side of that equation is covered in is professional monitoring worth it.

Do not solve false alarms by turning the sensor off. Deleting or disarming the only motion sensor on the ground floor to stop pet alerts quietly removes your interior detection layer. Better options, in order: enable the maker's pet mode, remount to the height the manual specifies, aim the sensor away from furniture and stairs the pet uses, and only then reduce sensitivity.

If your pet is over the published ratings (a 90 lb shepherd exceeds every figure in the table), PIR pet immunity is not going to work reliably, on any brand's paper. The honest alternatives are door and window sensors plus glass-break detection with no interior motion at all, or cameras with software person-detection doing the interior layer; several no-fee options for the camera route are in best no-subscription security cameras, and system-level picks are in best self-monitored systems with no monthly fee.