Wireless PIR Motion Sensor

What's the motion sensor for home security?

Motion sensor (detector) is the core component for your security system, and it can detect the illegal intrusion through picking up movement from someone who is in your home when they shouldn't be. The motion sensor can utilize multiple technologies to detect movement in specific area. Passive infrared detection is one of main technology used in these sensors. If a sensor is triggered, the alarm signal will send to alarm control panel either via hard-wiring or wireless radio frequency. Once the control panel receive the signal and determine it's security breach, alarm set off immediately.

We will provide some comprehensive information about this type of sensor, read below info, you will know how to install, use motion sensor properly.

The function of motion sensor in your security system

Sensing the motion of human being is the main purpose of motion detector. The sensor can work in day/night 24 hours with passive infrared detection theory. The sensor with PIR elements for sensing the infrared energy changing inside guarded space.  Some advanced motion sensors can record the video footage, once it detects the motion.

Motion sensor is widely used in many applications, and it can pickup movement in your bedroom, windows or doors being opened or closed, the motion detectors can:

  • Notify you when detects illegal entry
  • Making door bell sound when someone approaches the door/windows
  • Alert you when people access into restricted areas in the home
  • Motion sensor based lighting to save energy

The types of motion sensor

Typically, there are two kinds of motion detectors: passive motion sensor (PIR) and active motion sensor (AIR). Each uses unique technology to sense motion in the specific area. The passive infrared motion sensor only receives the infrared energy from protected objects and environment, it doesn't emit any infrared ray or energy, by reading changes of energy in the surrounding area, the detector can pickup the motion. Active sensor emits the infrared rays or micro-ware radiation to detect the movement.

Passive infrared (PIR)

passive infrared motion sensor detection

Detects infrared energy level. Passive infrared detectors are the most widely used motion sensor in intrusion alarm systems. When the alarm is armed, the installed motion sensors are activated. The sensor can detect motion in the guarded areas, forming a protective "grid". If a moving object blocks too many grid zones cause infrared energy levels change rapidly, the sensor will be triggered.


Microwave motion detection

Emitting micro-ware using Doppler effects, and measuring the reflection off a moving object. The micro-ware can penetrate majority objects and detects a larger area than passive infrared sensors.

Dual technology motion sensor

Dual technology motion detection

Dual technology combines two different technologies for accurate motion detection. It can effectively reduce the false alarms rate. A Dual-tech motion sensor is built-in two different cores; passive infrared, micro-ware. Since each operates in different areas of the spectrum, the dual-tech motion sensors are as likely as other types to cause the false alarms. In order to trigger the alarm, both sensors (Infrared and microwave) need to be tripped. 

How to place the motion sensor?

The best way to install the security alarm system is to hire professional installer. They will know how to setup sensors. However, you may choose to use the DIY home alarm system which requires setup by yourself. Before begin the installation, make sure to read the installation manuals comes with sensor, since the manual will included detail information for usage and placement recommendation for installation. 

Please bear in mind that motion sensors are not error-proof. Without properly installation and usage, there are instances in which there could be false alarms.  Especially animals insects and foliage will lead to false alarms.

Tips to avoid false alarms for motion sensor

Making sure to read the instructions that come with our detector, this can help you to increase the effectiveness of your sensors and prevent the false alarm, also you can consider the following tips for sensor placement.

1. Avoid install the PIR motion sensor near to heating sources, it should be 10-15 feet away from heating vents. The swift change in heat and a cloud passing quickly over direct sunlight shining into your bedroom, the sensor could be tripped.

2. Place the motion sensors at "entry points" - ares where people will walk through to get inside, like the stairwell or main hallway. That means an intruder will trip the sensor before they are headed. Install more sensors in bedroom where have valuables need to be protected.

Placement diagram for motion sensor

3. Pretend to be potential intruder, and walk through your property, and access where intruders are most likely to enter, what the path they will chose for break-ins. Install the sensors into these key points and avoid to have blind detection areas. Keep in mind that motion sensor with limited detection range between 50 and 80 feet. Place the sensors to a front and back door, garage door or patio door to prevent illegal enters for perimeter protection.

Placement for motion sensor

4. For sensitive or property usage of the motion sensor. The motion sensor should be installed where intruder will walk parallel to the sensor. Avoid place the sensor toward the intruders, it will not detect the motion accurately. Place the sensor on the walls of hallway or narrow pathway can allow sensor to detect the motion when an intruder walk alongside.

Tags: Motion sensor, Home alarm system