Motion Detection

Motion Detection Featured Alarms For Security

A motion detector (or motion sensor) is an electronic device that is used in detecting a physical movement in a designated area. They are usually used in security systems as trips for remote alarms, triggers for automatic lights, or other related applications. As a security, motion detectors are used in doorways or windows of a building to monitor that area of the building. Once they detect motion, motion detectors generate an electrical signal to alert a homeowner that some condition has changed around the area that is being monitored. At first, the signal is sent to the individual’s home security’s control panel, which links to the monitoring center from where a homeowner is alerted to a potential threat in their home. Some motion detectors work as a radar scanner, while others are based on vibration, infrared radiation, or sound.

Types of Motion Detectors

Motion detectors are helpful, in that they stand guard, prepared to react to movement in your door, window areas, or your doors being opened and closed, or even a broken window. Here are the various types of motion sensors:

  • Passive Infrared (PIR) Motion Sensors. This kind of motion sensor detects body heat (infrared energy). They are the most widely used motion detectors in home security systems due to their ability to pick up the slightest of movements in a building. Passive infrared motion sensors activate the minute your home security system is armed. The system uses a thin film of pyroelectric material that responds to infrared radiation by generating electricity. They detect heat and movement in the areas under close observation, forming a “grid.” Once a moving object blocks too many grid zones, it causes the infrared levels to change rapidly, which leads to the sensors being tripped.
  • MicroWave (MW) Motion Sensors. This kind of motion detector sends out pulses and gauges the reflection of a moving object. MicroWave sensors cover a larger area than Passive Infrared motion sensors. The drawback of this type of motion sensor, however, is that they are exposed to electrical interference.
  • Dual Technology Motion Sensors. Dual motion sensors combine the features of two motion sensor types to lessen false alarms. For instance, Microwave Infrared motion sensors can be combined with Passive Infrared motion sensors to deliver you the attributes of both systems. The wisdom is that since both sensors operate in different areas of the spectrum, and one is active while the other is passive, they are unlikely to cause false alarms. This is as both sensors have to be tripped before they’d be triggered. In addition, they help provide a much more secure vigilance around the area being monitored.
  • Area Reflective Motion Detectors. Area reflective motion sensors send out infrared rays from an LED and use the reflection of those infrared rays to measure the distance to the intruder it detects, provided the burglar is within the designated area being protected.
  • Ultrasonic Motion Sensors. This type of motion detector emits pulses of ultrasonic waves and gauges the reflection of a moving object. Once it measures the reflection, it triggers the alarm to alert you to the presence of a foreign object in the area under watch.
  • Tomographic Motion Detectors. Tomographic motion sensors transmit radio waves and sense when those waves are interrupted. This type of motion detector can see through walls and objects. They are placed in a way that forms a radio wave net that travels over large areas. They are a reliable solution for homes, warehouses, professional storage units, and other places that require important security.
  • Vibration Motion Detectors. This kind of motion sensor detects vibration and then send a signal to the control panel, informing you of a foreign presence outside your home. Vibration motion sensors can be purchased or made at home.

Local Sensing VS Area Sensing

Motion detectors sense different types of human or object movement. There are two types of motion sensing which include:

  • Local Sensing. Local sensing refers to the sensing of motion at specified locations. Some of the sensors used for local event sensing include contact switch, visible/infrared light (LED/Laser) beam, piezoelectric sensors, and piezoresistive sensors, among others.
  • Area Sensing. Area sensing refers to the sensing of motion in a particular field of view. The motion sensors very often used for this purpose consist of active/passive infrared motion detector, footstep detection sensing, microwave Doppler sensor, video, ultrasound motion detection sensor.

Tips for Keeping Your Motion Detector Sensors in Top Working Condition

Here are some of the things you should know and the ones you must avoid doing to keep your motion sensors working as they should:

  • Do not point your indoor motion detector in the direction of a window. Doing this will result in a false alarm. Also, depending on the type installed, pointing your motion sensor toward the window will cause them not to work as efficiently as they should. For instance, a Passive Infrared (PIR) motion sensor won’t be able to catch an intruder through a glass but could be misled into raising a false alarm by a concentrated burst of the sun or a car headlight.
  • To have them working in top condition, ensure always to keep your outdoor motion sensors clean. Grime or dirt on the front window, for instance, can inhibit them from being able to sense motion.
  • Avoid keeping your indoor motion sensors near an HVAC vent or in a drafty place. Motion sensors trigger a false alarm when too much hot or cold air is blown onto them.
  • Test different placements to determine the most effective position for your motion sensor. Motion sensors have blind spots. So, it is sometimes hard for them to detect motion when there is a barrier. For instance, a Passive Infrared (PIR) motion sensor might not be able to identify an object that is moving directly toward it. If you are unable to find the perfect position for your motion sensor, it is recommended that you place two motion detectors at perpendicular angles so they can make up for each other’s shortcomings. This will help ensure that they are better positioned to detect movements.