- Passive Infrared (PIR)
It can detect body heat. Passive infrared sensors are widely used motion sensors in home security systems. When your system is on, the motion sensors are activated. Once the motion sensor warms up, it can detect the heat and movement in the surrounding areas, making a protective grid.
- MircoWave
It sends out microwave pulses and tracks the reflection of moving objects. It covers a larger area than the infrared sensors, but it is susceptible to electrical interferences and is more expensive.
- Dual Technology Motion Sensors
Motion sensors may have combined features in order to reduce false alarms. Dual Technology motion sensors are less likely to cause false alarms because, in order to trigger an alarm, both sensors must be tripped.
- Area Reflective Type
It emits infrared rays from an LED source. Using reflection of rays, the motion sensor can measure the distance of the objects and also detects if the objects are within a specific area.
- Ultrasonic
It can measure the reflection of moving objects and send pulses of ultrasonic waves.
- Vibration
These sensors detect vibrations. Homemade motion sensors can also work, but they are often unreliable.