Motion Detector Placement
An automated motion detector contains a motion sensor. The sensor turns the movement that it has sensed into an electrical signal which is then transmitted to a motion alarm.
PIR and Occupancy Sensors
In most cases, motion sensor circuits for alarm systems are called PIR (Passive Infrared) sensors. It measures heat that radiates from objects in the field of view of the motion detector. Anyone detected moving alters the "normal" state that the motion sensor is accustomed to. For example, if a body passes by a stationary dresser which is covered by a motion detector, the movement will be sensed and the alarm will go off.
An occupancy detector is a motion detector that is integrated with a timing device. When motion has stopped for a programmed period of time, it triggers a light extinguishing signal.
Wireless Motion Sensor Placement
To start with, most motion detectors can detect between fifty and eighty feet. With that in mind go through your house and figure out where an intruder would most likely enter and what path they might take after entering. For example, the majority (over two-thirds) of burglars enter the home through an unlocked front, back or garage door or window (http://crimeinamerica.net/crime-prevention-tips-that-work-3/). It might make sense to place motion detectors close to each of those locations. Patio doors are another common point of entry for a thief.
Intruders usually head right for the master bedroom. Consider putting a motion detector in the hallway or stairway leading to that and other rooms.
Another place burglars will enter is through a window. Glass break detectors (these sound an alarm when broken glass is sensed) have a range of about 20 to 35 feet. They can be set up in rooms in a line of sight to the windows. So, you would mount the sensors opposite the windows. One glass break detector can cover several windows in one room.
Avoid aiming a PIR sensor at heating vents, where the sunlight shines in or at a radiator.
Installing a Motion Detection Device
Consult with your technician if you are having a professional system installed. If you are installing the sensors yourself, keep these points in mind:
- Remember, that motion detectors work best when the intruder walks past it as opposed to walking toward it. So, find the appropriate walls that an intruder would walk parallel to. For example, you might install a sensor about 4 to 6 feet in on a hallway wall where the hallway leads to a master bedroom. That way, the intruder will have to pass directly in front of the motion detector.
- Read the installation instructions that come with your sensor. They will include the proper positioning specs for the sensor.
- Use a drill and screws to mount the sensors into the wall keeping it away from the heat source.
- If not wireless, route the wire to the control panel. You might have to route the wire along the baseboard and/or through a wall to get there.
There are many motion detectors and sensors to select from that will meet the needs of your household.