In this article, the author writes about some concepts in equipment and operation necessary in a perimeter security system.By: Ricardo Abréu*
The fundamental basis of any intrusion protection design is always perimeter protection, which is the first line of defense of the area to be protected. Unfortunately it is usually not the most protected point or the most desired to protect. The fundamental cause is the possibility of the generation of endless false alarms or unwanted alarms.
According to several marketing research institutions (VB reseach, Reuters, etc.) by 2010 perimeter protection will exceed the US$4 billion mark with a growth of more than 10% compared to the previous year.
When you want to design a perimeter protection system, the guidelines to follow are the following:
to. System durability and performance
b. Minimum level of false alarms
c. Maximum detection capacity
d . Minimal maintenance
and. Ability to pinpoint the exact point of intrusion
f. Ability to integrate with other security lines
There are several methods of perimeter protection:
to. Surface mounting on fences and gates
b. Buried sensors to detect pedestrians
c. Micro wave or infrared open area sensors
d. Sensors with analytical video analysis
The most common system is perimeter protection using different types of devices or sensors on the fence, the most common are the following:
Fiber Optic Sensors: In which the fiber cable acts as the sensor mounted on the fence, protecting large distances by using only the fiber as a conductor of a laser beam with ranges greater than 80 Km, measuring the variations of environmental alterations in the fence. It is very effective without electrical power in the field, monitoring and analyzing the signals continuously with mathematical algorithms. This type of system is maintenance-free and by not carrying power or electrical cable helps us reduce maintenance, avoid thunderstorm attractions and RFI / EMI.
Impact detectors: Inertia or electromechanical detectors. These detectors can be installed on the fence or gates attached to a processor (which requires power supply and alarm communication to the control center) with a maximum range of 100 meters. They tend to have a high level of false alarms due to their vibration condition, any rain or wind causes them to fire and usually require ambient stations to minimize their sensitivity due to the effects of wind, rain, etc.
Microphone cables: This system consists of a usually coaxial cable with two to more conductors that are capable of detecting different types of environmental variations, usually installed on the fence and provides the information to a processor located on the fence covering no more than 150 meters from both ends. It requires electrical power, communication and output of wired alamas to the processor and the same amount of cables for the central processor in the control room.
Buried sensors: Usually, two coaxial conductors are required, although some manufacturers use a single coaxial with the two conductors under the same configuration. The principle of operation is to make an electromagnetic field protected by the two conductors, creating an alarm when coming into contact with the protected perimeter or when stepping on the sector under the conductors, however, the levels of false alarms are large in open areas due to the passage of animals, changes in the environment or presence of EMI / RFI.
Open or volumetric aerial sensors: They are usually micro-wave type sensors or passive or active infrared energy detection sensors. These products were very popular in the 80s and 90s but the level of false alarms and their short range has reduced them to a minimum of use.
Detection using video analytics: The use of video analytics has grown in recent years as a solution to surveillance using intelligent video and motion detection systems. Cost is an important factor as many cameras are required to protect very long distances, and of course, wiring and maintaining both is the installer's number one enemy.
*Engineer Ricardo Abréu is the Manager for Latin America and the Caribbean of Future Fibre Technologies. If you want you can write to the email [email protected]
