|
The microwave detectors transmit envelope pattern that is same as the ultrasonic device but the range of frequency emitted by the microwave detector is longer. Approximately, the range of microwave detector extends up to 30 m.
Working
The microwave detector transmits microwave energy at extremely high frequency range. Using the Doppler effect, any change in transmitted frequency reaching the receiver is analyzed to determine the size of the object and the distance moved. An alarm starts in the event of a breaching by an intruder.
Application
The microwave detector finds its application in place where robbery or theft is of chief concern. Outdoor microwave intruder detectors are particularly suitable for use in conjunction with closed circuit television (CCTV), security lighting and other switched devices to provide a reliable outdoor trap protection system for compounds, yards and other similar sites. Indeed microwave detectors do have significant advantages, being
unaffected by air currents or noises that can prove troublesome to its ultrasonic counterpart. Apart form this, it can also be used to detect a large vehicle at a distance of 100 m. The range is governed by the target size.
|
