Also known as the Motion Sensor, this is one of the most important parts of your home security system.
The typical Motion Detector is known as a PIR or Passive Infrared sensor. They set off your alarm when the sense changes in infrared energy or “heat” levels which are caused by somebody moving within the area protected or “seen” by the motion detector.
They don’t give off any energy of their own. They just “see” or “sense” the infrared energy given off by the persons who move into its space.
They’re quite simple, not very expensive, and are great for protecting sizeable areas of you home.
Although you may want more than one, depending on the size of your home, even one motion detector will do a pretty good job. Why? Because when a burglar breaks in, they are greedy, and will typically run all over your house looking for stuff to steal, likely crossing the path of the motion sensor.
Most standard security systems “kits” come with one motion sensor.
Want to know how much area your motion sensor will cover? Here’s a good rule of thumb:
Pretend that your head was positioned right where you plan to have the motion detector mounted. And pretend that you were looking straight ahead, just where the motion detector would be “looking”.
The amount of space that you could see with your two eyes, without moving them – looking straight ahead, is approximately the area that the motion sensor can “see”. That’s about a 90-degree view, and a typical detector might have a distance range of 40 feet.
Many motion detectors are “pet immune”. That means that a small pet, maybe up to 50 pounds, can run around free in your house while you’re gone, and they won’t set off the alarm. If you have a larger pet, you can “upgrade” to a sensor which can go up to about 75 pounds, or even 100 pounds. Other folks who have large pets simply find some way to seclude them in an area where the motion sensor can’t “see” them.
If you have a large pet, and the thought crosses your mind, “I just won’t use the motion sensor when I’m gone,” please think again. The motion sensor is a critical part of your home security system.
Motion Sensor