Motion Detectors

A motion detector is a device that contains a physical mechanism or electronic sensor that quantifies motion that can be either integrated with or connected to other devices that alert the user of the presence of a moving object within the field of view. They form a vital component of comprehensive security systems, for both homes and businesses.

There are basically three types of sensors used in motion detectors spectrum:

• Passive infrared sensors (PIR)
• Looks for body heat. No energy is emitted from the sensor.
• Ultrasonic (active)
  sends out pulses and measures the reflection off a moving object.
• Microwave (active)
  Sensor sends out microwave pulses and measures the reflection off a moving object. Similar to a police radar gun.