Motion Sensors

They are used for interior protection. While door and window sensors and glass break detectors protect against an intruder coming through a door or window, a motion sensor does not care how the intruder got in.
As soon as the intruder walks into a room protected by a motion sensor sense movement and send reports its status to the control panel for processing. While the Intrusion Detection System is armed, an activated system cause a local alarm and sends a mobile message OR call mobile which are saved earlier in control panel.

Advanced security systems include Passive infrared (PIR) motion detectors. These sensors “see” the infrared energy emitted by an intruder’s body heat. When an intruder walks into the field of view of the detector, the sensor detects a sharp increase in infrared energy.
Of course, there will always be gradual fluctuation of heat energy in an area. So, PIR detectors are designed to trigger the alarm only when infrared energy levels change very rapidly.See above pictures for details.