A burglar alarm/intruder alarm is a proven deterrent against burglary and crime. There are two main types of wired burglar alarms:
These systems rely on sounders to both deter the burglar and also warn neighbours of the intrusion. A system will normally have 1 external sounder as a minimum, this can be added to by having an internal siren as an extra deterrent inside the property, an additional decoy box on other exterior elevations to provide extra visual deterrent outside, or an extra external sounder could also be used.
It is also possible to install a ‘telephone auto dialler’ onto a bells only system, which can notify a set of telephone numbers, both land line and mobile, of the alarm activation. These have the advantage of immediate notification without incurring on-going charges for central station monitoring.
These systems have all the features of the ‘bells only’ system with the addition of being monitored by a central station via a telephone line or radio link (GSM). When the alarm is triggered, it sends a signal to the central station, which then notifies the key holders and police of the alarm. These systems are a requirement of some contents policies.