Easy Break In Through Glass Windows. Think Twice!

A glass-break sensor, also known as an audio discriminator, is a kind of area-based security system, in the sense that it “listens” for sound frequencies in an area of up to approximately 35 feet diameter around it. A glass-break sensor can recognize the frequency generated by the sounds of: (i) splintering wood and (ii) breaking glass. If it senses any audio signal in the frequency range of these sounds, it immediately triggers off an alarm.

A glass-break motion detector is better than window switches because a single glass-break sensor can cover all the windows in a room unlike a window switch alarm that covers just one window where it is installed.

How glass-break detectors work

Until recently, glass-break detectors were gadgets based on a “single technology”. They were designed simply to pick up the audio frequencies of splintering wood and breaking glass, but at many times they were fooled into setting off an alarm by the sounds of crackling lightning, two drinking glasses colliding with each other (Cheers!), or by any other sound that ended up mimicking the audio frequencies generated by the sounds of splintering wood and breaking glass.

The glass-break sensors of today use what is called a “dual technology”. The new-age glass-break detector has to first hear a “thump” or a “thud” kind of sound (bang your head on a wall to figure out how a “thump” or a “thud” sounds) followed by a sound frequency of breaking glass/splintering wood to activate the alarm. The logic is simple: when an intruder wants to break into your window, he will first hit some object on it (which is the “thud” sound), and only then the glass will break, making the characteristic glass-breaking sound.

The new-age sensors are more expensive than the “single technology” ones, but they are considered to be worth every cent.

Factors to be considered while selecting a glass-break sensor

Before going in for a glass-break sensor for your office, you should keep in mind that it is a secondary security device and, sometimes, may trigger off a false alarm. Here are some other factors you need to know about how glass break sensor works

• Every window in your office need not be equipped with a glass-break sensor. Only inaccessible windows that might be accessed by burglars using a ladder or windows in rooms where sensitive data or inventory is stored need to be equipped with such detectors.
• Do you need wired or wireless glass-break security? If all other security systems in your office are wireless, then you could consider installing a wireless glass-break detector.
• Figure out how many glass-break sensors you actually need. Remember that one sensor in a room will normally cover all the windows in that room.
• If you run a restaurant or any business that is near a gas utility, then you should buy a system that detects carbon monoxide too.
• Do you have adequate security where you want and are confident enough to feel that a glass-break sensor will be just an added backup? If yes, then go for a “single technology” system.
• If you have a surplus budget and need a good glass-break detector, then go for the new-age systems that use “dual technology”.

Installing a glass-break sensor

Although professional contractors are recommended to install glass-break systems, here is a small DIY to try on a weekend:

• Get the following tools ready: screws, screwdriver, drills, and other tools that are used to pass wires through walls.
• Read the installation instructions found in the manual.
• Place the sensor/detector on a wall or a ceiling in such a way that it covers all the windows in the room. The sensor is the piece that detects the sound frequencies. Remember the diameter of the area covered by a glass-break system is up to 35 feet.
• Do not place or mount the sensor near any insulation.
• Now fix the sensor on the chosen place using the drill and the screws.
• Take the wire from the sensor across the ceiling and head it to a corner in the room. From the corner, route the wire to the control panel (the control panel is a place that the sensor will send the signal to, when it detects the sound). Remember to connect the wire to the proper outlet on the control panel or you will not get to hear the alarm bells ring.
• If passing wires across ceilings and corners, and then concealing them raises your blood pressure, then a wireless glass-break detector will serve you fine.

Here are a couple of precautions:

When installing a glass break motion detector system remember that some states in the US regulate the installation procedure - they say that only professionals do the installation. You must also take into account the national codes about electrical wiring.

If your office windows are covered by drapes, then any sound of breaking glass will be muffled by the drapes and, hence, will not be picked up by the glass-break sensor.