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Key Considerations when choosing a Perimeter Intruder Detection System

Perimeter Intruder Detection Systems (PIDS) act as a visible deterrent to potential intruders and keep a constant watch on a site’s perimeter to provide the opportunity for early detection of an attack. 
Fence walls

Choosing the right solution can be difficult, the following factors can have a substantial impact and should be considered where relevant:

Ground surface/mounting position/burial medium

Will a free-standing system operate over gravel, concrete, tarmac, grass, sand, bodies of water or a combination of different media along its length?

Will a ground-based system be buried in sand or clay-based soil?

The performance of a PDS can vary considerably.

Local topography 

Are there any undulations in the ground surface? Undulations occurring over the distance of a metre - up to several tens of metres - can shield the presence of an intruder from some detection technologies, particularly in the case of microwave systems, or active or passive infrared.

Are there any surface objects (roads, fences, lighting columns etc.) to be negotiated?

Conducting bodies – Microwave and other active electromagnetic systems can be affected by metal or other conducting bodies close to their detection zones both above and below ground. This includes metallic fences, vehicle access and also flowing water. The presence of such bodies in proximity to the planned route of the PDS must be taken into consideration.

Zone lengths 

Long zone lengths can make it difficult for operators to identify the cause of an alarm and/or locate an intrusion. Some PDS provide positional information on intrusion location. PDS zones should be matched with the field of view of one or two CCTV cameras where video verification of alarms is required. It is, however, important to perform tests at all zone ends to ensure that camera footprints overlap sufficiently and detection capability is not compromised.

Mounting of sensors, processors, junction boxes 

These system elements should be mounted such that detection is expected before any components of the system are reached by an intruder. For example, mounting the processor box for a barrier-mounted PDS on the fence fabric is not recommended.

Future site expansion 

Provision may need to be made for any forthcoming expansion plans at the site, such as additional capacity within cable ducting and electrical enclosures. Consideration at an early stage is likely to save costs

Your security partner should perform a thorough evaluation and work carefully through these considerations prior to recommending any solution. Our next blog provides a simple evaluation of the different technologies available. 

Our guide to perimeter detection provides more detail to help get you started. It is available here