How Alarm System Work

How Alarm System Work

Arby Babaian Home Security Systems Leave a Comment

How Alarm Systems Work

Alarm systems are over 100 years old! How alarm systems work haven’t changed as much as one may think even though one of the earliest being patented by Alexander Pope of Boston. Bet you learned something new today. His system was very similar to modern alarms, consisting of magnetic contacts placed at the openings and interconnected by pairs of wires to a battery and a bell. The disturbance of any of the openings closed the circuit and caused the bell to ring. This system was, of course, much simpler than modern alarms and its main disadvantage was that it could be defeated by cutting the wire. Even though alarm systems have been around for a long time and a lot has changed, there are many principles in alarm systems that remain the same.

Basic Principles of Alarm Systems

There are two basic “levels of protection” provided by a security system: exterior (or perimeter) protection and interior protection. Each has it’s place for protecting what matters most to you. Some alarm systems are made up of one or the other. The ideal security system uses a combination of both types.

Perimeter Protection

Exterior or perimeter protective devices generally consist of sensing mechanisms attached to doors and windows leading into the home. These devices are wired in such a way that they will sound the alarm if an entry is attempted and send an emergency call for help to a central monitoring center. Magnetic contacts are the most widely used for perimeter protection. These devices work with a switching mechanism. The contacts are attached to doors or windows and, when these protected areas are opened the magnet moves away from the switch and the alarm is activated. In the event that an intruder attempts to bypass the magnet contacts by breaking the glass in a door or window, specially developed sensors can detect the sound of glass breaking and activate the alarm. It’s a basic concept that has evolved over the years but door and window contacts are relatively stayed the same for the most part. Today, most of this is done with wireless alarm systems but the magnet is still the same.

Interior Protection

Even though in a perfect world perimeter protection would be enough for most alarm systems, there are many scenarios where perimeter protection isn’t enough. It is important to have a method for detecting an intruder should they elude the perimeter security system. This is where an interior system comes into play. One of the more commonly used interior protective devices are motion detectors. There are three basis types: infrared, microwave and ultrasonic. These protect the interior by detecting the body heat or movement of an intruder and sounding the alarm. Most alarm systems today have a motion detector included in them. They aren’t the same as the older ones, since new technology has helped with avoiding false alarms, they still are the most used alarm system equipment for inside the home.  Motion detectors are, in my opinion, the  most effective piece of equipment for any property when no one is there. Other alarm system interior devices include glassbreak sensors, image sensors (motion detector with a camera that takes pictures), and even some video cameras.

Fire Protection Systems

Both smoke and heat detectors should be included in any security system for fire prevention and life safety. Many times fire alarms systems aren’t talked about.  Like the security system, a fire prevention system will not only make your protection complete, but also reduce your homeowner’s insurance premiums. Fire alarm systems not only save lives but maximize your insurance discounts. Smoke detectors should be located in each bedroom, outside all sleeping areas and on all levels of the home. They work by detecting the presence of smoke particles in the air.  New technology has made it easier to protect your home by connecting one smoke and/or heat detector to other ones in a property. There are even 3 in 1 devices that have heat, smoke, and temperature sensor all in one small device.

Now that you know the basics of alarm systems you can take a look at the new technology and have a great foundation to a life safety system.  Make sure you have all your needs met with your security system. Once you have all your needs you can then take a look at all your wants and add on different things to make your life, not only safe but convenient too.


How alarm systems work back in the day, and today. Call us for more information.

Have more questions? Contact us here at All About Security at 317.559.3500. We’ll be happy to answer them for you!

Until the next time stay safe and informed Indianapolis!

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Arby Babaian

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