Fence Alarm Perimeter Protection

Perimeter Security Overview

Outdoor security sensors detect intruders as soon as they enter a protected area and before they can gain access to people or valuable assets. In a correctional environment, security sensors can be used to immediately detect prison escape attempts. A quality outdoor security system demonstrates a significant return on investment by reducing the risk of theft, damage or personal injury.

Outdoor sensors can be used either to complement indoor security sensors or as primary security in situations where indoor security is not feasible. To protect assets at both manned and unmanned sites, outdoor security sensors are a practical solution for remote sites where guards are not a viable alternative.

Outdoor sensors face challenges not found in indoor security situations. Environmental conditions, such as temperature extremes, rain, snow, animals, blowing debris, seismic effects, terrain and traffic, must all be taken into account. When functioning under these adverse conditions, the system must continue to maintain a high probability of detection while minimizing false alarms (alarms with unknown causes) and nuisance alarms (environment-related alarms), both of which can reduce confidence in the security system's performance.

The "vulnerability to defeat" characteristics of different sensors is important to consider. The hidden nature of totally covert sensors makes them difficult to avoid and less subject to vandalism. Intruders are not even aware of their presence. On the other hand, some sensors present an imposing appearance that can provide a deterrent effect. Volumetric sensors create a large invisible detection field that makes bridging difficult.

Closed circuit television (CCTV) cameras are an important element in outdoor security. CCTV assessment is used to verify whether or not alarms reported by intrusion detection sensors are valid intrusions or false/nuisance alarms, ensuring that only valid alarms are responded to. Use of assessment is especially important for remote sites where response to nuisance alarms can be particularly costly.

Outdoor sensor types

Many types of outdoor sensors exist in the market. The most appropriate sensor to use depends on several factors: perceived threat and level of protection required; effectiveness of the sensor against the threat; site conditions and environment; sensor cost-comparisons; and the life cycle or cost of ownership of the sensor. Many of our outdoor sensors can be classified into four groups: volumetric sensors, fence-mounted sensors, video motion detection sensors and barrier sensors.

Volumetric Sensors

Volumetric sensors generate an invisible detection field that locates intruders moving through that field. As the field of detection is invisible, these sensors are very difficult to evade. Immune to most environmental conditions, they are often used in sterile zones and may be totally covert.

Fence-Mounted Sensors

Fence and wall-associated sensors are above ground detection sensors that are attached to an existing structure. They are activated when an intruder disturbs the detection field or when vibration due to cutting or climbing on a metal fabric fence causes an alarm.

Video Motion Detection Sensors

A video motion detection system transforms the assessment-only ability of CCTV cameras by analysing the video output signal to create the detection field. Video monitoring also provides additional information to help identify the source of an alarm and whether or not it is valid.

Barrier Sensors

Barrier sensors are a two-in-one security option. They provide both a barrier to intrusion and a sensor system for detection. Taut-wire sensors are an example of a barrier sensor that offers an almost zero false alarm rate and unsurpassed probability of detection.

These sensors have virtually no environmental limitations and are able to provide reliable service for many years.

Whether your security requirements call for one of these sensors in stand-alone detection, or combined with CCTV assessment in an integrated system, security management should be a consideration. A security management system integrates and automates the control of the sensors and sensor alarms, significantly reducing the workload of the operator. These systems can provide maintenance information to help diagnose problems with individual sensors and allow sensors to be adjusted from the central control.

Planning your site security

All outdoor security procurements should be planned with close attention to detail. To determine your security needs, you must accurately assess the level of risk. A complete understanding of the consequences of intrusion is necessary to define the scope of the system required.

Whether you need a system to secure possessions, to protect people, or to detain people, the threat will determine the strategy of the system.

Once the threat has been outlined, you should proceed with a site survey for any terrain constraints, environmental conditions or human factors that would affect the project requirements. It is also important to consider how the operators will use the system. A thorough understanding of the threat, site constraints and expectations is the key to establishing a realistic budget.

When it comes time to designing your system, you should consult with experienced professionals. The design stage involves choosing products that will effectively secure the perimeter. In some cases, this may include modifying the site to accommodate the security features you desire. Our team is available to work with you in assessing your security needs. We will use your budget and aesthetic considerations, to determine which technological application will most effectively meet your unique requirements.

BDI Security Solutions Ltd provides resources and information for every step of the process. From help with writing your system specifications to arranging proper acceptance testing plans, we are working to secure your interests.

With confidence that you have chosen the products to fit the requirements of both the environment and the nature of the risk, it is time to write the specifications for bidders. This stage is extremely important to ensure that you receive the security you require.