Choosing a home security system

Don't rely on your barking dog to alert you to burglars. If you want maximum security, have a burglar alarm system installed. Here are the main types of systems available. 

• These types of alarms go off if someone opens a door or window. Magnetic sensors are installed on closed windows and doors, and adjacent switches are recessed into the frame. When the door or window is closed, the magnet and switch are close enough together to form an electric circuit. If the window or door is opened when the system is armed, the circuit is broken and the alarm sounds.
• For additional protection, fit your windows with security screens, which are window screens interwoven with wires that form a protective circuit that sounds an alarm if cut.
• Glass-break alarms that adhere to any glass window or door and sound when the glass receives any abrupt shock are another option.

• These types of alarms go off when something moves inside a room, cutting across the invisible beam cast by the detector. These kinds of detectors should be installed across doorways and other passageways about one metre (three feet) above the floor (if they're too low, they may ring when your pet saunters by).
• It's also a good idea to position sensors in the corners of each room near the ceiling to survey crucial traffic areas.
• All alarm systems consist of sensors that are connected to a control box, a remote-control key switch to turn the system on and off, and an alarm that rings a bell or siren or dials the police (or security company) or your cell phone. The control panel should be near the door you use most often, but out of reach from the outside if a window is broken.
• The most efficient burglar alarms are hard-wired systems that combine both perimeter alarms and motion detectors. However, there are also wireless systems that use radio frequency signals to monitor the components, many of which simply plug into wall outlets or are battery-powered.

• Unless you're an expert do-it-yourselfer, you'd probably be wise to have a full burglar alarm system installed professionally.
• If you don't want to spring for a full system, use individual motion detectors that scan single rooms and sound an alarm if anyone enters.