Before you are able to make an educated decision on what type of alarm system you may need, it is important for you to understand how they work. 

In its simplest form, an Alarm System is an electrical circuit with magnetic contact sensors (Mag’s) on entry doors and windows. When a door or window is opened the sensor detects the interruption in the flow of electricity and triggers a warning signal such as a siren.

In addition to magnetic contact, many systems also include motion detectors (Passive Infrared Detectors) that monitor large areas inside the house as well as beams outside the house. When something moves within the detector's range or crosses through the beams the sensor activates the alarm. The more sophisticated motion detectors are able to distinguish between the threat of an intruder and the nocturnal wanderings of the family pet, reducing the possibility of false alarms.

When these perimeter sensors, interior motion detectors and exterior beams are part of a stand-alone system, the siren and flashing lights are the only deterrents for discouraging the intruder and preventing a break-in. In a monitored system however a signal is sent via radio or telephone to a central monitoring station (control room). Operators at the control room monitor these signals 24 hours a day via computer and dispatch armed reaction officers to the client’s property when an alarm signal is received.

How Many Zones?

The “size” of the alarm system dependent on the number of zones required, which in turn is determined by peripheral devices attached to the control panel.

Example: 4 Zone Alarm System

• Zone 1: Entry Exit Doors.
• Zone 2: Lounge and Passage PIRs.
• Zone 3: Outdoor PIR.
• Zone 4: Panic  

By breaking the property up into clearly defined zones, one is easily able to identify which area has been violated, or rather where an intruder has gained entry. Zone violations light up on the keypad, thereby allowing alerting the user as to the exact location of the intrusion. So in the above example if Zone 3 triggered the control room would know that it was the outdoor Passive Infrared detector that went off.

Clearly defined zones also assist the control room when dispatching reaction officers. A single internal zone violation may be a false alarm, while multiple zone violations starting on the perimeter and moving internally will alert the control room to the fact that the intruder may still be on the premises, the reaction officer will then act accordingly.