Intruder alarm glossary
We have produced this layman’s guide to Intruder Alarms – to make life easier for you by cutting through the jargon.
We will start by describing the Alarm Receiving Centre, then examine the different ways of signalling, look at police guidance and finally, review the different types of intrusion detectors.
Alarm Receiving Centre (ARC)
When you have an intruder, there’s no point in having an alarm unless you can be confident that someone is instantly aware and ready to act.
That’s why we have our own dedicated Alarm Receiving Centre - to monitor remote alarms. We are there to help 24 hours a day. And that goes all the way - right down to checking that the battery is properly charged. The moment an alarm is sounded, one of our trained operators takes over, calling keyholders or the police, whichever is appropriate.
Bell box
The distinctive SECOM bell box is an external sounder which has a self contained high output two tone sounder incorporating a strobe light for visual indication. All electronic components are contained within a secure fully tamper proof enclosure.
Signalling methods
BT redcare GSM
Redcare GSM works on a BT telephone line backed up by the O2 cellular network. This is known as dual path signalling. It gives warning of a line cut and loss of signalling. This is one of the most secure forms of signalling available today.
BT redcare BT redcare is more secure than a digital communicator with the added enhancement of alerting the ARC if the line is cut or tampered with. Police guidelines mean that they will not be summoned if the line fails. Instead, the keyholder will be called to investigate for themselves. This device is used for residential and business premises.
Dualcom
This device is another form of dual path signalling. A Paknet radio transceiver transmits the alarm signals and a digital communicator gives warning if there are radio signal problems.
Digital communicator
Digital communicators work a bit like a computer modem. They transmit basic data, such as an alarm from the protected premises. They won’t notify the ARC if the phone line has been cut and can’t send a signal if the line is engaged. They are most commonly used for smaller residential systems.
Police guidelines (DD:243)
DD:243 are guidelines introduced to help alleviate false alarms; reducing police time wasted in attending sub-standard and problematic systems. The guidelines outline that alarmed areas need to be covered by two or more detector devices using different technologies (see Detection Devices). Only if the second detector is activated within 30 minutes after the first device will the police respond. A single alarm activation alerts the ARC who notify the keyholder.
Confirmed light
This is a light programmed to come on as soon as any secondary detection device is triggered. Although not a strict DD:243 requirement, it does help overcome potential health and safety issues.
Once a keyholder is called to attend the premises after one detection device has been triggered, it is reassuring to know that a warning light will let them know if a second device has been triggered, suggesting that an intruder is inside. As a matter of course, SECOM Plc fits a confirmed light at the final exit on every system that requires police response.
Detection & protection devices
Magnetic reed contacts
These devices use magnets fitted to doors. When the door is closed, two metal strips secured within a glass phial come together, completing a circuit. Once the door is opened, the circuit is broken, activating the alarm. There are four types:
Flush contacts are fitted inside the door frame and are invisible when the door is closed. Surface contacts are housed in PVC boxes and are generally used for external doors. Heavy duty contacts are as surface, housed in metal boxes with stronger magnets. They are generally used for ill fitting doors. Shutter contacts are fitted to the floor and are generally used for roller shutters and metal sliding gates.
Passive infra red movement detectors
For domestic and office applications, SECOM normally employs wide-angle ‘quad zone logic detectors’. These are intelligent devices that provide very stable detection, recognising the difference, for example, between humans and rodents. Electronic chips process the information even further to filter out false alarms.
Dual technology movement detectors
These detectors combine infra red and microwave detection technologies and both have to be activated to cause an alarm.
Vibration detectors
These are normally fitted to door or window frames and are designed to detect high and low frequency vibration within a range. They can be adjusted to suit local conditions.
Break glass detectors
Break glass detectors are fitted over or next to shop fronts or other vulnerable glazing. They detect the sound of breaking glass, together with the accompanying change in air pressure.
Infra red beams
A transmitter projects an infra red light beam to a receiver unit. Interrupting the beam triggers an alarm. In hostile environments, dual or twin beam units are used, where both beams have to be interrupted. They can be used inside or outside.
Personal attack buttons
These units employ two buttons, which have to be pressed at the same time to activate an alarm. They work around the clock and can sound an audible alarm, or can silently alert SECOM’s receiving centre.
We are experts in all combinations of security measures and can tailor a solution that is exactly right for you, please contact us.
