Network Perimeter Alarm System Solution
With the development of society and the improvement of security awareness, modern security technology has been widely used. In some important areas, such as parks, chemical companies, airports, military bases, weapons and ammunition depots, prisons, bank vaults, museums, power plants, oil depots, etc., in order to prevent illegal invasions and various sabotage activities, traditional preventive measures are to set up some barriers or obstructions (such as iron fences, fences, wire fence nets, etc.) at the periphery of these areas, and arrange for personnel to strengthen patrols. In the current situation where criminals use advanced science and technology and criminal methods are more complicated and intelligent, the traditional preventive measures can no longer meet the needs of key departments and key units for security work. The human defense is often affected by factors such as time, location, personnel quality, and energy, the loopholes and mistakes are inevitable. Therefore, the installation and application of an advanced perimeter alarm system has become a necessary measure.
Composition of Perimeter Alarm System
The perimeter alarm system generally consists of four parts: front-end detectors, signal transmission network, central alarm control panel & alarm center management software, and sound and light alarm devices.
In order to strengthen the preventive effect of the security system, the perimeter alarm system is usually linked with the monitoring system, so that it can grasp the situation of the alarm scene in time. The monitoring system can implement 24-hour real-time monitoring of the perimeter area and carry out computerized management so that managers can understand the actual situation of the surrounding environment in a timely and accurate manner. In case of illegal intrusion, it can automatically alarm and display the alarm area; automatically record the alarm and automatically forward the alarm information; equipped with video surveillance, it can observe and record the actual situation of the deployment and control site in real-time and intuitively, providing reliable information for alarm verification and post-alarm processing.
Except for the different technology used by the front-end detector, the other parts of the perimeter alarm system are similar.
① Positive infrared beam
Advantages: low cost, high performance-price ratio, and can be used for clear and straight fences.
Disadvantages: easy to be disturbed by small animals, fog, snow, rainy weather, and sunlight, so it is necessary to exclude tree branches and shade.
② Multi-beam infrared wall
Advantages: Can be used in open perimeter areas.
Disadvantages: Cannot be installed concealed, affecting the appearance of the building; the shared perimeter of adjacent villas cannot be determined to cross the boundary direction; the irregular perimeter shape brings inconvenience to the configuration of the infrared light wall
③ Electric security fence
Advantages: It is a prevention technology for tangible objects, which is less disturbed by the environment. It is currently being promoted to be used for perimeter prevention in residential communities.
Disadvantages: poor viewing, the fence-like protection is depressive and lacks humanity; there can be no plants around to avoid false alarms caused by branches and vines.
④ Leaky cable
Advantages: Invisible intrusion detection, mainly used in banks, airports, prisons, military bases, and other occasions, and can also be used in places with more complex terrain in the wild.
Disadvantages: Not suitable for residential community perimeter alarm.
⑤ Vibration cable/optical fiber
Advantages: suitable for applications with high explosion-proof requirements.
Disadvantages: Not suitable for invisible perimeter prevention such as residential community perimeter alarm, villa open gardens, river courses, and unmanned substations.
Choice of Perimeter Alarm System
Currently, there are three most commonly used perimeter alarm systems: video surveillance, infrared beam, and electric security fences.
(1) Video surveillance
The intelligent video motion detection and tracking system are applied to the perimeter alarm, and it makes full use of digital video image analysis and processing technology to digitally process the surveillance image of the perimeter scene. It also analyzes human behavior, whether it is normal movement or ready to cross Perimeter, or throw objects or leave goods on the edge of the perimeter, etc.
When the intrusion is confirmed, the system is activated to alarm and various linkages. The image directly shows the situation of the perimeter alarm scene, which changes the invisible condition of the traditional perimeter.
The video surveillance system has obvious advantages such as visualization, automatic tracking, and recording and playback, but the disadvantages are also obvious. For example, the monitoring effect is poor in haze weather or night, there are monitoring blind spots, the inability to actively warn, and the aging damage.
(2) Infrared beam
The infrared beam has no blocking effect, and its function is mainly limited to alarm. The advantages are low cost and easy construction. However, it is susceptible to environmental restrictions such as high and low terrain conditions, twists, turns, and bends. The protection level is low, and it is not suitable for harsh weather. It is vulnerable to high temperature, low temperature, strong light, dust, rain, snow, fog, frost, and other natural climates. Impact, high false alarm rate.
The positive infrared beam is currently the most used product in the community perimeter alarm system. When an illegal intrusion occurs, an alarm must be generated, but the intrusion has already occurred, which will pose a greater threat to personal and property safety. Therefore, in order to prevent illegal intrusion and various sabotage activities in communities, in addition to the positive infrared beam system, some shields or obstructions (such as iron fences, glass on the walls, iron wires, etc.) are generally installed at the periphery of the community. Arrange personnel to strengthen patrols.
Due to the technical defects of the infrared beam itself, it is easy to be affected by other media to generate an alarm when used outdoors. Natural environments such as rain, fog, strong wind, etc. may cause alarms, and the false alarm rate is extremely high.
(3) Electric security fence
The electric security fence has the three functions of deterrence, blocking, and alarm. It has the characteristics of active prevention, strong environmental adaptability, and is not affected by temperature and climate changes, and is not affected by environmental factors such as greening, trees, small animals, terrain height, and degree of tortuous.
The electric security fence enclosure alarm is accurate in positioning. It has a strong deterrent. If the alarm is triggered and the criminal still wants to forcibly invade, the system will respond with a strong electric shock feeling.
The electric security fence is especially suitable for the perimeter protection of some important places and units, such as factories, airports, warehouses, high-end villas, high-end residences, and other large-scale defense areas.
Suggestion: The three can be combined and used at the same time to achieve the best prevention effect.