What is an intruder alarm system?
For those who don’t know, intruder alarm systems, more commonly known as burglar alarms, are security systems designed to detect and deter unauthorised access to buildings or an area. The primary purpose of an intruder alarm is to alert the occupants, security personnel, or authorities when an intrusion is detected. These alarms are widely used in residential, commercial, and industrial settings to enhance security.
Intruder alarm grades
Intruder alarms are graded according to their level of security and reliability. The grading system is most commonly used in the UK and Europe and is outlined in the European Standard EN 50131. There are four main grades to help users and installers select an appropriate level of security for a given application.
Grade 1 Intruder Alarms:
This is the lowest level of security and is appropriate for low-risk environments such as residential properties and small businesses where the risk of intruders is minimal.
Grade 2 Intruder Alarms:
Grade 2 is suitable for low to medium-risk properties, again this is most suitable for small to medium-sized homes or businesses. You would most likely use this grade where the risk of intrusion is moderate.
Grade 3 Intruder Alarms:
This grade is suitable for environments with a medium to high risk of intrusion. Typically, grade 3 alarms are installed in commercial or industrial premises where the value of the property or assets justifies a higher level of security. Grade 3 introduces more sophisticated features such as enhanced resistance to tempering and more reliable communication methods.
Grade 4 Intruder Alarms:
This is the highest level of security and is designed for high-risk environments where there is a significant threat of intrusions, such as Government buildings and banks. Grade 4 systems provide the highest level of security and usually include backup systems and advanced tamper resistance.
Understanding Intruder Alarm System Grades
The grade shows how much protection the system gives: Grade 1 is the most basic, while Grade 4 offers the highest level of security. Each grade has rules about things like the type of detectors, power supply, and how well the system can resist tampering.
Remember, the alarm system is only as strong as its weakest part — the overall grade is set by the lowest-graded component. See below a table to explain which grade should be used for different applications.
| Grade | Risk | Common Applications | Response & Protection |
|---|---|---|---|
| 1 | Low risk | Homes and residential properties | Basic deterrent only. Minimal protection, no police response required. |
| 2 | Low to medium risk | Small offices and retail shops | Guards against opportunistic theft. Includes sensors with some anti-tamper features. |
| 3 | Medium to high risk | Warehouses and commercial premises | Defends against more skilled intruders. Requires police response and advanced tamper detection. |
| 4 | High risk | Banks, government buildings, data centers | Highest level of security. Uses multiple detection devices, anti-masking sensors, secure signaling, and continuous monitoring. |
What to know when choosing an intruder alarm
Choosing an appropriate grade depends on the specific security needs, location, the value of the assets, and the potential consequences of a security breach. It’s also best to keep in mind that these grades are just one aspect of designing a comprehensive intruder alarm system. An intruder alarm system is always best accompanied by other security components like CCTV, access control, and other physical security measures.
All of the above can be purchased with Norbain, provided you have a trade account with us. Feel free to get in touch to see how we can help with your security needs.
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