Security Alarms Jargon Busting

Security alarm systems seem to be getting more complicated. Whether you’re a homeowner, a key–holder at work, or you’ve some responsibility for your organisation’s premises, you’ll need to know a bit about your alarm system. So if you don’t know your PIRs from your PA Buttons, here’s a bit of jargon–busting…

Magnet Reed Contacts

Often used in homes on doors. Basically these involve two metal strips which, when they come together, complete a circuit. When the door is opened the circuit is broken and the alarm is activated.

PIRs (Passive Infra Red Movement Detectors)

Mainly used in domestic or office settings and positioned high up (usually in corners) to detect movement. They can spot the difference between humans and other intruders – such as mice – to avoid false alarms.

Dual Technology Movement Detectors

These combine infra red and microwave technologies. Both have to be activated making false alarms very unlikely.

Vibration Detectors

Normally fitted to door or window frames. They detect high and low frequency vibration and can be adjusted to suit local conditions.

BGDs (Break Glass Detectors)

Usually fitted over or next to shop fronts. They detect the sound of breaking glass and any accompanying change in air pressure.

Infra Red Beams

You’ll have seen these in the movies! Thin beams of light that trigger an alarm when broken. Dual or twin beam units are sometimes used – both have to be interrupted to set off the alarm. They can be used inside or outside.

PA (Personal Attack) Buttons

Units with two buttons that must be pressed at the same time to activate an alarm. They can sound an audible alarm, or silently alert an ARC (Alarm Receiving Centre) – a place where remote monitoring is provided by the security system provider.