What does it mean when the alarm on the infrared motion sensors sounds?
We may have obtained alarms on our infrared motion sensors. SJGR uses passive infrared motion sensors on investigations. This type of sensor operates similar to the way an IR thermometer does. It does not send out any beams, it reads incoming temperature signatures usually calibrated for any large object over 40 pounds. This depends on the sensor used. It’s looking for a human sized object’s body temperature to pass through its coverage zone. We have this energy being emitted from our bodies and it is what this sensor will pick up on. It will not be set off by most pets with the exception of dogs over 40 pounds. If this meter alarm sounds and there is no natural cause, it just detected movement in it coverage area of something that was giving off a temperature signature that was at least equivalent to a small child.