ACTIVE IR BEAMS
Active infra-red beams allow an invisible fence to be created. The fence is made up of two units, transmitter and receiver. The transmitting unit sends invisible infra-red pulses to the receiver at the same time as a synchronizing signal. The receiver will only analyze the infra-red signal when the synchronizer signal is received. The receiver will not recognize continuous light – either visible or infra-red – thus making it practically immune to direct sunlight or deliberate interference. Transmitters and receivers are usually mounted in a column containing a number of units that can be angled to crisscross each other and form an invisible net. Columns are fitted with anti-tamper and anti-climb devices so that they cannot be easily compromised.
For extreme environmental conditions, heaters, thermostats and fog discrimination modules are available.
Although some manufacturers incorporate features to reduce nuisance alarms such as fog and animals the systems are susceptible to problems with dense fog, snow and vegetation.
Active IR beams can be installed on either side of a physical barrier or in open space. They are ideally suited to vehicle entrances and road ways.