Entry Motion sensor Detection

A door entry alarm having infrared detection comes as an area motion detector or with a narrowly focused infrared beam between two sensor devices, one producing the beam and one reflecting or receiving the unbroken infra red beam.  The entry alert or chime occurs when someone moves in the protected area or breaks the invisible infra red beam. The chime alert or alarm is made by the motion detector or is sent by the infra red motion sensor to a wireless receiver (where the alert is sounded) in another area or room.