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When large glass surfaces, walls and ceilings or showrooms and shelves, etc. need protecting, active infra red barrier detectors may be used for both indoor and outdoor applications. These are not affected by direct sunlight and have a range of 20-30 m depending on where they are used.
Such devices use a transmitter and receiver principle to project an invisible infra red beam across an open path. These systems are reliable and have a long service life. Further operating security is achieved when the receiver is exposed exclusively to the beam of one transmitter. The capacity of transmission is not split and secure operation is guaranteed. Detectors can normally be mounted on top of each other so that the effective distance between the beams can be reduced to 10 cm apart. An intruder crossing between the transmitter and receiver destroys the invisible beam which causes an alarm signal to be generated at the control panel.
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