What is the purpose of a motion detector in a security system?

Motion detectors, sometimes called motion sensors, are an instrumental part of any security system. Motion detectors provide a backbone for your security system, a network for your property to sense any and all motion in a given area monitored by the motion detector. In the event of a break-in, motion detectors allow you to sense when the intruder enters, where they are, how they’re moving, and most importantly, sends an alert to your control panel to alert your monitoring center. Motion sensors can also be connected to additional pieces of security equipment, such as floodlights and cameras to be activated by any motion detected in their area as well.

The purpose of motion detectors is a simple one, fitting for the backbone of a security system: sensing presence. When a security system is in away mode and armed, it’s fitting then that there should be no motion in a home. With motion detectors equipped in your system, your system can quickly and easily notice when someone who is not meant to be there is in your home or on your property, and have your system notify your monitoring sensor.

How do motion detectors work?

Although there are different ways of measuring it, all motion detectors are searching for the same thing: change. Motion detectors work by constantly monitoring an area, seeking a difference in the area from the last moment. These include the smallest changes, such as vibrations and temperatures, in order to tell if any movement has been detected in the area being currently monitored. There are several ways motion detectors achieve this goal, and the two most popular technologies for motion sensors are Active Ultrasonic and Passive Infrared, or PIR.

Active Ultrasonic motion sensors send out ultrasonic sound waves. These sound waves are such a high frequency that humans can’t even hear them! These sound waves then reflect off of objects, returning to the origin point of the sensor. If a moving object is to interrupt this reflection of sound waves, your control panel will be notified instantly and take the predetermined course of action – typically setting off your home alarm and alerting your monitoring station.

Passive Infrared, on the other hand, detects infrared energy in an area. Rather than emitting soundwaves, these PIR sensors emit infrared waves to detect temperatures. By merely detecting the change in temperature in an area, these sensors can detect the presence of an object or person. Living things, whether that be humans, pets, or wild animals, emit a lot of heat, making the heat signature they give off an easy choice for differences to detect in an area.

Less popular than PIR and Active Ultrasonic, but still within the marketplace of motion detectors are tomographic motion sensors, vibration motion sensors, and microwave motion sensors. Tomographic motion sensors involve having multiple nodes installed throughout an area, which creates a network between them. When the link between these nodes is broken, i.e., a person or object is interrupting the connection, the alarm will go off. Vibration motion sensors, a much simpler form of motion sensor, detect people by vibrations; those typically made by footsteps. Finally, microwave motion sensors let off microwave pulses. Microwaves will reflect off objects, much like ultrasonic sensors detect motion.

How to properly place motion detectors during install

Motion sensors have limited range, which makes where and how you place them incredibly important during installation. As with all pieces of security equipment, it’s recommended you consult a security professional for input on where to install. Give your home a run through in which you take note of each and every entry point a potential intruder could take. Doors, windows, and garages are among the most common places that burglars would enter through. Motion sensors are also best placed parallel to paths that intruders would take – against the wall of a hallway, rather than the end of the hallway, for instance. Corners are the best locations for motion sensors, creating virtually no blind spots. Additionally, mounting them high on the wall will maximize the range that your motion sensors have. Main entrances and master bedrooms are also key locations to place motion sensors; main entrances are the easiest point of entry for intruders, and intruders tend to go straight for the master bedroom in burglaries. Ensure nothing is blocking your motion sensors, such as bookshelves, as this will prevent the motion detector from working correctly.

Why you should include a motion detector in your alarm system

Motion detectors help to protect your home in a simple, practical way. By constantly being vigilant for any motion in your home while armed, any step a home intruder makes in your home won’t go unnoticed. The bread and butter of any home security system, a motion detector provides the service of keeping a constant monitor on the home and quickly informing the monitoring station that someone is in the home when there shouldn’t be. In addition to the many security benefits granted from a motion detector, there’s also a plethora of options that can assist with smart home living.

Motion sensors can be used to send notifications directly to your phone, not just to your alarm. This can be helpful in sending you alerts when parts of your house are entered by small children and pets, before they enter and risk harm to themselves. Motion sensor lights are among the most common uses of motion detectors; this can be for anything from turning porch and driveway lights on during your approach, and can also help with energy saving by automatically turning off lights when there is no motion detected in a room.

Motion sensors are possibly the most important part of your security system. Without them, we wouldn’t have window and door contact sensors, and we’d have no way of being aware of intruders. By detecting that at the source, and contacting you and your monitoring center when that happens,  motion sensors play a major role in home security. Contact Cunningham Security for any questions you may have when it comes to what motion sensors are right for you and where is best to place them during install.