Electronic Intrusion Detection Systems

[Name of the Institute]

Contents

Taut Wire System1

Principle of Operation1

Sources of Nuisance1

Strengths and Weaknesses2

Vulnerability to Defeat2

Active Infrared Sensors2

Principle of Operation3

Sources of Nuisance Alarms3

Environmental Considerations4

Strengths and Weaknesses4

Vulnerability to Defeat4

Ported Coax Buried Line Sensors5

Operating Principle5

Sources of Nuisance Alarms6

Environmental Considerations6

Strengths and Weaknesses6

Vulnerability to Defeat7

Table - Summaries of Electronic Intrusion Detection Systems7

References9

Electronic Intrusion Detection Systems

Taut Wire System

Taut wire intrusion detection structure is designed to detect and prevent intrusions physically by unauthorized person into sites with high security.

Principle of Operation

The principle of operation of Taut Wire is that at the core of its system, there is installed an electro-mechanical sensor. This sensor senses a predetermined amount of deflection of wires, sends a signal to SPRU - Sensor Post Reporting Unit. The SPRU communication this information related to the alarm signal over a serial connection. It registers detection when one more than one sensors sense a deflection in their wires in a direction that is horizontal (Office of Nuclear Security and Incident Response, 2011). This deflection in the horizontal direction is created by a fixed amount of pressure exerted along the length of the wire or by a wire being broken or cut. The SMS - Security Management System receives the data, rings an alarm and offers a clear indication of the location and type of intrusion attempt on the visual screen. Within the categories of sensors that detect intrusion, taut wire systems are point-of-detection, terrain-following and visible sensor (Peck, 2005).

Taut Wire systems detect intruders with substantial size or mass while rejecting other stimuli relating to environment. The probability of detecting (PD) a intruder who is a human being passing through the perimeter boundary at locations that are random is greater than 97% with a confidence factor of 95% (http://senstar.com). The system rejects false alarm rates as it does not detect an intruder who exerts a pressure of less than 15lbs or 7 kg on the wires. The system has a lesser amount than one alarm that is false per 3 months per kilometre.

Sources of Nuisance

The main sources of nuisance in this intrusion system are the animals of average to large size which press on the fence while nesting or grazing. This can cause a false alarm.

Environmental Considerations

One main advantage of Taut Wire systems is that there exist very few sources of nuisance alarms (NA) if the system is correctly maintained and installed. A possible source of nuisance alarm is a severe ice storm (Senstar Corporation, 2011). However, this occurs extremely rarely. If enormous amounts of ice start building up on the wires, it can cause physical damage to the system. Besides that, temperature fluctuations have a tendency to alter the tension of the wires. This causes sensitivity concerns. Consequently, it results in additional maintenance due to shrinking and stretching of wires. Another cause of environmental concern to the system is the impact of a highly corrosive system on the Taut Wire. Such an environment can cause increased reliability concerns and maintenance if the system is not made up of aluminium or stainless steel ...