Perimeter security system is used to control and detect crossing of the border of the guarded object. The most common means of detection are vibrating, capacitive and radio-radial sensors, but this is not a complete list of possible options.
Active infrared detectors are widely used for perimeter protection, they respond to the intersection of the beam. The detector consists of two parts: a transmitter and a receiver, which should be directed at each other and situated in direct mutual visibility. The sensor responds to interruption of the beam, which is fixed by the receiver, which, in turn, transmits the alarm further. Multiple-beam infrared sensors are used to avoid false activations. Multiple-beam infrared sensors also serve to increase (if necessary) of the barrier beam.
Non-contact optical detectors of object position.
Are used to determine availability or absence and the position of the object in controlled space. Photoelectric sensors may be used to detect objects at distances from several millimeters to several tens or hundreds of meters. The sensor consists of a radiator, which generates optical radiation in a determined space, and a receiver which responds to the light flow, reflected from the object its interruption. Source and receiver can be located in the same or in different housings. There are three main types of photoelectric sensors:
The radiator and receiver are located in different housings, but on the same axis. Luminous flux is directed to the receiver, which responds to the interruption of the beam. This type of sensor can detect even transparent and mirror objects, and amplitude can reach 150 meters.
Radiator and receiver are arranged in the same housing. Radiator light is flashed from the reflector and fixed by receiver. Sensor works out when the beam is interrupted by opaque or translucent objects. Generally, amplitude of reflex sensor is up to 10 meters.
Radiator and receiver are arranged in the same housing. Radiator light is reflected diffusely and perceived by the receiver. The range of the sensor depends on the flashing possibility of the controlled object and is typically from one to two meters.
Vibration detectors react to mechanical vibrations of the fences elements or special sensor cable, which is installed in the same enclosure. To adjust the vibration detectors, particularized software is used, that allows to receive real waveforms of recorded signals. The sensitivity of the vibration detectors – it is an indicator that can be adjusted over a wide range, but also depends on the cable uses, fencing, choice oflocation and step attachment. Ability ofdetection byvibration perimeter protection systems is directly proportional tothe set level of sensitivity.But thereisa downside: if you increase the level of sensitivity, rate of false abrasions will be also increased. Thus, for each case the final adjustment of the sensitivity level should be carried out according to the results of test system.
Radiowave system of perimeter security consists of two conductors and control device. Conductors must be arranged parallel to each other at a certain distance. Through conductors constantly passes amperage that generates a magnetic field. If some external objects flow into this magnetic field, control device will detect violation of the perimeter.
Perimeter security system can be built on the basis of security CCTV systems, if motion detectors, crossing of the line or object recognition algorithms are added. In order to provide perimeter security, crossing of the line sensor or motion detector can be used. While using crossing of the line detector, it is important that the focus of the camera does not get any external moving objects (leaves, twigs, etc.), which can cause false working out. Using of the motion sensors saves resources, as cameras can be adjusted in such a way, that they record the video only after the working out of the detector.
If you want to install perimeter security system, consult our specialists by phone (044) 525-28-53, 525-28-63 or send a request on our web-site.