How Glass Break Sensors Work

There are multiple layers of protection that home security systems can offer. Motion detectors sense when someone is moving within the house. Entry detectors sense when a door or window is opened. Glass break sensors are less well known but make a valuable enhancement to a home alarm system. Alarm companies in Palm Desert can install these glass break sensors which alert to an intruder breaking glass to enter your home.

How do they work?

Glass break sensors detect the sound frequency of window glass being hit. Sometimes referred to as the ‘flex’ signal, this is stage one of detection. Stage two is the detection of the sound frequency of the glass shattering. Stage two, which occurs microseconds after stage one, sets off the alarm.

When can you use them?

Glass break sensors can be on at all times, when either in the ‘stay’ or ‘away’ modes. This provides security for both when you are at home or out. Many alarm systems have a gap in protection because of the limited protection when a system is in ‘stay’ mode. In ‘stay’ mode, usually, only perimeter sensors are armed, not interior motion sensors. This means that the protection offered to you when you are home is limited. Someone could enter through a window and freely move through your home. Having glass break sensors help boost that protection level. They significantly reduce the chance of someone entering your home undetected. When you think about it, you would rather have your property protected while your family is in the home than when they aren’t.

How are they set up?

Sensors generally cover a range of up to 20 feet. This means that one sensor can often cover several windows or glass doors within a room. This means glass break sensors are ideal to use in an open-plan home. Because home layouts vary, home alarm companies can configure the setup for optimal security.

How are they tested?

Glass break sensors have a well-designed test system. This means that when the home alarm company installs your sensors, they can test them to show you they work. By switching a sensor to test mode, a clap test can be performed, to ensure the sensor detects the sound. The light for stage one will show on the sensor at this point if it is working correctly.

Glass break sensors are carefully calibrated to avoid ‘false’ alarms. This means that you do not need to be concerned about breaking a drinking glass or having the television too loud. Glass break sensors will not recognize those as window glass breaking.

When glass break sensors may not be suitable

They can not work properly if you have shatterproof windows or have security film applied to the glass. Shattering these would not emit sound at the frequency which glass break sensors can detect. Items like heavy curtains can also disrupt the sound received by the sensor. It is important to have the home alarm company calibrate the sensitivity of the sensors.

If you’re looking to enhance your home security and fill that protection gap, glass break sensors are a worthy consideration.


photo credit: highmarkb Custom home builders in Minnesota via photopin (license)