Passive Infrared Motion Detectors- These detectors are also known as PIR detectors. The technology they utilize is "passive infrared". The device is mounted on a wall or in the corner of a room. It sends invisible fingers out into the covered area in several layers. The top layer goes the furthest and averages about 60 feet straight ahead and 35 feet on the sides.
The center layer of beams spreads the area about mid way and the bottom layer sweeps the room closest to the detector. These beams individually measure the infrared temperature of what ever they land on and look for a clash of temperature against that point. For example if a beam lands on your couch and knows what temperature it is, when you walk in front of the couch your temperature is different and causes a violation. You would be hard pressed to match the temperature of everything in your home as you walk about and that makes motion detectors hard to compromise.
Passive motion detectors have a microchip in them that will adjust the device for slow and methodical temperature changes. This way as your room warms up and cools down during an armed alarm period, you will not get a false alarm.
Some motion detectors are designed to be mounted in the ceiling and spread a 360-degree cone downward. Some are recessed to replicate an electrical outlet and various other combinations are available for the James Bond like clients. Most often the device is an aesthetically pleasing small device that is mounted 5-7 feet high in the corner of a room.
Passive inferred motion detectors will not see through walls or windows as they will consider touching one of them as their final destination and begin calculating the temperature. The beams project forward only and will not bend around corners. If your device is placed where a beam can go into an area with an opened door, it will protect the interior of that area as well. Once the door is closed the beam will terminate on that door.
Motion detectors are not going to protect every square inch of your home or business unless you invest in many of them to accomplish that. Instead you should intelligently place them as an interior trap in an area or areas most likely to be violated by the creep or creeps that want to take your marriages or worst off violate you personally. Usually one placed properly on the main floor and one on the lower level if you have one, will serve as good traps. Stairways are often a good thing to consider when placing the device, due to the fact that you will prevent unauthorized passage from one floor to the next.
An alarm installer should always place a device where it will best serve the user and achieve the most coverage. Many an installer has indicated to forgo this concept so that they can install the device in an area that is …