A security alarm is a system designed to detect intrusions, such as unauthorized entry, into a building or other areas, such as a home or school. Security alarms protect against burglary (theft) or property damage, as well as against intruders. Examples include personal systems, neighborhood security alerts, car alarms, and prison alarms.
Some alarm systems serve a single purpose of burglary protection; combination systems provide fire and intrusion protection. Intrusion-alarm systems are combined with closed-circuit television surveillance (CCTV) systems to record intruders' activities and interface to access control systems for electrically locked doors. There are many types of security systems. Homeowners typically have small, self-contained noisemakers. These devices can also be complicated, multirole systems with computer monitoring and control. It may even include a two-way voice which allows communication between the panel and monitoring station.
Rickmansworth (/ˈrɪkmənzwərθ/) is a town in southwest Hertfordshire, England, about 17 miles (27 km) northwest of central London and inside the perimeter of the M25 motorway. The town is mainly to the north of the Grand Union Canal (formerly the Grand Junction Canal) and the River Colne. The town of Watford is 5 miles (8 km) to the northeast. Rickmansworth is the administrative seat of the Three Rivers District Council. The confluence of the River Chess and the River Gade with the Colne in Rickmansworth inspired the district's name. The enlarged Colne flows south to form a major tributary of the River Thames. The town is served by the Metropolitan line of the London Underground and Chiltern Railways from London Marylebone to Aylesbury railway station.