Intruder Alarms and Security


Security and Intruder alarms have been around for many years, and have become increasingly sophisticated in an attempt to outwit thieves. Since the early ages we have tried to protect our belongings and property from being stolen or damaged by people who either cant afford it, or are jealous of what you have!

The market currently sells three types of intruder alarm system, outlined below:

  1. DIY systems that are easy to install without the need for wiring
  2. Basic control panel, and detection system with wired movement detectors 
  3. 'Intelligent' systems which can provide maximum protection with the incorporation of auto dialers and more complex types of detection etc..

    A big dog may also be an option, but they can be more expensive than a good system!!

If you are intending to install a system, remember you pay for what you get! Cheep is not best!

The control panel is the heart of the intruder alarm system, (type 1 or 2 above) must be located in a reasonably secure part of your property, don't forget though, you will need to access the panel to type in your security code to set and unset the system (and on re-entry of the property, you only have a short time to type in your code)!  

Type 3 systems (as above) will have a panel that the keypad can be located separately from the panel, so the control panel can be hidden away.

All intruder alarm panels now have a battery backup, so in the event of a power failure, your property should stay protected for a period of around 4-5days. The external siren will also have a battery inside it for backup in the event of a power failure (don't forget that if you get to open the cover on one, as the tamper switch will make the alarm sound!!)

All of the above systems can utilize several different types of detection. The most common being :

  • Passive Infra Red detectors (PIR) - for detection of movement
  • Magnetic door and window reed switches - to detect opening of doors and windows
  • Vibration detectors - detects breaking glass
  • Pressure pads - put under carpets for detection of weight on the floor
  • Dual Tech Sensors - (similar to PIR but better!) incorporates Microwave and PIR detection.

More complex systems can also make effective use of an autodialer, so that in the event of an alarm, the dialer will call either the police, or other persons you select it to call (depending on the type of system installed).

There are many advantages and several disadvantages with some of the above systems, I have covered these further below:

1. DIY intruder alarms (wireless)

If you want an honest opinion - a waste of time!! These systems provide a reasonable form of security, and are better than nothing, but are susceptible to outside interference.

Though DIY wireless systems form a quick and cheep method of installing an alarm, without the need to disturb decoration of the property etc, they are prone to some fundamental Flores. 

Being a wireless system, each form of detection utilizes radio to transmit a signal to the panel: this needs a battery to run it, and as we all know batteries soon go flat! 

It is also known in the trade that some 'technically minded' burglars have devised a simple 'radio jammer' which makes all battery operated detection useless, as the radio signals cannot communicate with the panel when a jammer is deployed!

And if that wasn't enough, these systems are normally limited to one keypad (on the panel) for the setting and unsetting of the alarm. 

So, as I said, these systems really are in my opinion, a waste of time!!

2. Basic control panel, and detection system with wired movement detectors 

This type of system can be installed by the DIY expert, but they are significantly more complicated to install that the wireless systems, are are often hard to setup if you are not experienced in this field. You are probably better advised to call a professional electrician or alarm engineer, to install a system for you. These systems are far more difficult to interfere with once the system is installed.

The control panels in these systems often have the keypad installed on the front of it, so when you are designing your system, bare this in mind!! Being a wired system, you will also need to find a route for your cables to run. 

These panels will show you which 'zone' has been triggered in the event of an alarm detector being activated. ie. ground floor lounge could be zone1, first floor zone2, etc.. (you can have many detectors per zone). 

Partial arming of the system can often be set with these types of panel (so night time setting disables the first floor detectors).


It is advisable to install no less detection than :

  • A magnetic reed switch on every door
  • PIR detector in every ground floor room, and one PIR upstairs (dual tech detectors are recommended over PIR)

I would also recommend that an auto dialer was installed.

3. 'Intelligent' intruder alarm systems

These systems are the most expensive systems on the market, but are not as expensive as some may think!

These panels will not have a keypad on them, and can be hidden anywhere in a property, as the keypad will be remote (and can be located anywhere near the exit to the property).

These systems are fully wired, (including the keypad), and have complete battery backup. The remote panels can be installed to tell you which area (rather than zone) that has been triggered in the event of an alarm (and even where a tamper has occurred). Again, the more rooms that have movement detection installed, the better protection you will have. These systems generally have options to tell you a 'log' of past events (who set the alarm, where it was last triggered etc). You can often set different codes for different people, or codes for the neighbour while your on holiday ( the advantage being these codes can control parts of the alarm rather than all of it if you wish).

This type of system can often be partially set (ie night setting will not arm the first floor). 

As you can see, there is little difference between the type 2 and 3, but of the two, I would recommend you spent a little more money, and installed an alarm with a remote keypad. This system is less likely to be damaged if a burglar does break in to your property (if the panel cannot be seen, it cannot be tampered with).

Things to remember on installation of alarms...

  • Battery backup, remember to connect the batteries!
  • Remember that all devices have tamper switches, (opening a cover will trigger a tamper alarm)
  • Opening the alarm box cover will trigger the alarm
  • Isolate the auto-dialer (if installed) before you test a system
  • Test your system regularly - it might look nice, but does it still work??
  • If you are performing maintenance, enter the engineers code (it silences all alarms)
  • After performing maintenance remember to reset the system!