Indoor Motion Detector Ajax Black

Description

This is the most repeated part of any alarm: the detector that watches a whole room. It is a volumetric PIR — it reads moving heat — with a 24-zone, 6-plane lens, which is what lets it pick up someone crossing sideways as well as someone walking straight at it.

It covers 12 metres at 88.5° horizontally and 80° vertically, is Grade 2 and has three sensitivity levels. The part households with animals appreciate most: pet immunity up to 20 kg and 50 cm tall, so the dog does not set the alarm off every night. It talks to the panel over 868 MHz Jeweller radio, up to 1,700 m in open space, and runs on a single CR123A battery lasting around seven years: fit it and forget it.

How we install it. Indoors, at 2.4 m — the height its own listing specifies — looking across the walkway rather than straight at the door: an intruder crossing the beam is picked up sooner than one walking towards the sensor. Never aimed at a window, a fireplace or a radiator, which is where nearly all false alarms come from. It goes on the SmartBracket, is registered by scanning its QR in the Ajax app, and before we finish we walk the room for the detection-zone test and run the signal-strength test.

If you also want breaking glass detected, the one that does both is the PIR and glass-break detector. The panel that listens to it is the Hub 2. Everything else is under Ajax indoor detectors.