An intruder alarm consists of a combination of detection, control and signaling devices. Every part of this equipment has been developed to fulfill a specific task within the system. The components are strategically placed in the building to be protected, in such a way that you can count on their constant, reliable and disturbance-free functioning.
There are basically 2 choices to when choosing an alarms system
Audible - The alarm sounds at the premises only. Response is reliant on somebody contacting the police to report it. Many forces have a policy whereby they will not attend audible only alarms unless there is additional evidence to suggest a crime is being committed, in other words they are not likely to attend unless someone reports a visual sighting or noises such as glass breaking.
Monitored - The alarm sounds at the premises and a signal is sent to an alarm receiving centre via your phone line, mobile network. The ARC will contact your nominated key holders or the police* (see standards page for more info)
There are also the options of hard wired or wirefree systems
Hard wired - Can be more reliable and cheaper than wire free, but takes longer to install. Most commercial alarms are wired
Wirefree - Easy to install but more expensive than a wired system. Used mostly in homes or small business premises.
Top technology
Police will respond to a monitored ETI alarm when an alarm-receiving centre notifies them. However, from Jan 2006 newly installed monitored alarms must also use "confirmation" technology to receive a police response. Here, people at the alarm-receiving centre check using either CCTV (to see an intruder), an audio connection (to hear an intruder) or something called "sequential confirmation". Sequential confirmation sounds a bit complicated, but basically this means detecting an intruder using sensors in a number of different places in or around you home - to spot if someone is moving around.