intrusion installation

Intrusion Detection 101

Facilities are susceptible to incidents of break-ins, intrusion, theft, and trespassing. Physical barriers such as fences and walls can only do so much – they are prone to physical tampering and scaling, which only delays intruders. The same can also be said for doors and windows.

A properly designed physical intrusion detection system helps protect assets and facilities by securing a site and mitigating the possibility of intruders entering undetected.


What is a Physical Intrusion Detection System?

A Physical Intrusion Detection System (PIDS) detects unwanted people or objects that are entering a restricted zone. It is often located at the perimeter of the facility, acting as an early detection system while the intruder is still at the perimeter and not yet inside a building or other interior area.

A PIDS is often integrated with other security components such as signages, security lighting, and loudspeakers. Detection at the perimeter enables the system to respond and engage these deterrence devices like lights and sirens.


Types of Sensors

Sensors are the backbone of an intrusion detection system. Here are some of the most commonly used sensors:

  1. Infrared Sensor

Infrared sensors detect temperatures, using infrared radiations to measure the temperature of objects.

Active infrared sensors emit and receive the radiation and are triggered when the signal hits an object. On the other hand, passive infrared sensors detect the radiations of nearby objects and are triggered when they detect an object with a much higher temperature than what is around, such as an intruder. A downside of this system is that it can also be triggered by passing wildlife.

  1. Microwave and Ultrasonic Sensors

Microwave and ultrasonic sensors work similarly to infrared sensors, but they emit and receive microwave radiations and soundwaves. These sensors analyze the waves that are bounced back to them –they should receive the same wave again and again in optimal conditions. The wave is altered when movement is present, which triggers the alarm.

  1. Door and Window Sensors

Door and window sensors are contact sensors and are effective in securing the perimeters of a building. A magnet is placed on the door or window, and the sensor is placed on the frame. The alarm is triggered if the magnet moves away from the sensor.

  1. Glass-break Sensors

This type of sensor detects vibrations in the glass. It gets triggered when the glass is hit or when it shatters.

Additionally, alarms can be bells-only, speech-dialer alarms, or monitored alarms.

  1. Bells-only Alarm: Makes a loud noise when triggered, intended to alert nearby people to an intruder or to scare off the intruder. Security response is not guaranteed with a bells-only alarm.
  1. Speech Dialer Alarm: This type of alarm calls or sends a message to “keyholders” (responsible for responding to an incident) when the alarm is triggered. The “keyholders” can then take the appropriate action in response to the intrusion.
  1. Monitored Alarm: These types of alarms are monitored by third-party service providers. The service provider usually calls the building to ask for password identification and may notify the stakeholders and the police if the potential intruder is unable to provide the correct answer.


Security Integrations for Intrusion Detection Systems

One of the most important performance measures for an intrusion detection system is its ability to maintain a high probability of detection while minimizing false alarms due to nuisance events. Nuisance events can be environmental factors such as wind, rain, animals, and even traffic.

Errors in installation can cause false alarms as well. Well-fitted and regularly maintained intruder alarms are crucial. Choosing the right detection technology to use depending on the location, level of protection required, monitoring, and method of response is equally important, which is why it’s essential to partner with experienced security integrators such as Absco Solutions.

There is no single technology that will provide a complete solution for intrusion detection – combining different technologies can reduce false alarms while leveraging their individual strengths. A multi-layered approach is best, which could include a combination of physical barriers, access control, video surveillance, and an intrusion detection system to secure an area.

If you have further questions about intrusion detection or if you’re looking for assistance in selecting the right technology for your system, please send us an email at Our team can help you create customized solutions that directly address your needs.


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