Although it’s no substitute for good locks and catches, an alarm system provides extra security and may help to deter intruders. The system itself must be reliable, and you and your family need to be disciplined in it’s use. If your neighbours are constantly subjected to false alarms, they are less likely to call the police in an emergency. In many areas, the police will not respond unless they are alerted by a member of the public or the system is professionally monitored.
Typical alarm systems
Alarm systems differ greatly, but there are two basic kinds: hard-wired systems, where the various detectors and sensors are connected to a central control unit by fine cable, and wireless systems that utilise radio signals that perform a similar function.
Both types include passive sensors that detect the presence of an intruder inside the house, and perimeter protection to guard likely means of entry. The best systems incorporate a combination of features in case perimeter detectors are bypassed.
The heart of the system is the control unit, which triggers a siren when it receives an alarm signal from a detector. The control unit has to be programmed to allow sufficient time for legitimate entry and exit. If it has a zone-monitoring option, you can activate door contacts or sensors in selected parts of the house – to permit freedom of movement upstairs at night, for example, while entry doors and down- stairs areas remain fully guarded.
The control unit must be tamper-proof, so that it will trigger the alarm if disarming is attempted by any means other than a key or the correct digital code. It is usually connected to mains power – but it should also have a rechargeable battery, in case of power failure.
Infra-red sensors can be strategically positioned to scan a wide area and will detect the presence of an intruder by measuring body heat. If necessary, you can opt for sensors able to distinguish between household pets and human beings.
Passive infra-red detectors are usually connected to the central control unit, but you can buy independent battery-operated sensors for protecting a single room.
Infrasonic alarm systems can detect the ultra-low noise levels created by the displacement of air caused by opening or closing doors and windows. Even when the alarm is set, neither you nor your pets will trigger it unless you open a door or window. Infrasonic alarms are particularly easy to install.
Entrances can be fitted with small devices that trigger the alarm when a magnetic contact is broken by someone opening a door or window. Other types of detector sense vibrations caused by breaking glass. A good detector is capable of distinguishing between a forced entry and vibration from other sources.
Most alarms have a siren mounted on an outside wall. These switch off automatically after a set period, but some continue signalling with a flashing light and some will automatically rearm themselves. It is important that the alarm is triggered by any attempt to tamper with it, either by dismantling or by cutting wires. Most sirens take their power from the control unit, but some are solar-powered. Many systems transmit a warning directly to a monitoring centre for a swift and reliable response to a break-in.
With most systems you can have a ‘panic button’ installed beside entry doors to press in the event of an attack. There are also portable wireless devices that can be carried on the person to summon help in the case of emergency around your home and in the garden. These devices trip the alarm even when the system is disarmed.
There are several DIY alarm systems that are quick and easy to install. However, you may need advice from the supplier of the equipment on the choice and siting of sensors and detectors. Consult your insurance company to check whether your choice of alarm affects your policy in any way.
Make sure the system will enable you to select the type and number of detectors you require, and that it incorporates a reliable tamper-proof control unit.
Wireless systems – which use secure coded radio signals to trigger the alarm – avoid the need for extensive wiring and can be extended to monitor sheds and garages. During installation you can programme each piece of equipment, including the control unit, with your own personal numerical code.
If you would like to improve the security of your home get in contact with First Call Electrician today. We can help you to choose and install the very latest security equipment. Call us today on 01245 330428.
First Call Electrician making homes and businesses in Chelmsford, Essex even more secure.