Glass break detector, also known as glass break sensors is an electronic burglar alarm devices that detect if a glass pane is broken or shattered. They are commonly installed near glass windows or doors.
These types of sensors typically use a microphone to monitor any noise or vibrations coming from the glass. Through detector circuitry, vibrations that exceed a certain threshold (some sensors can customize this) will be analyzed. Simple glass break detectors are using narrowband microphones tuned to frequencies typical of glass shattering, and react to sound above a particular threshold. Advanced ones compare the sound analysis to one or more glass break profiles using signal transforms similar to DCT and FFT and react if the amplitude threshold and statistically expressed similarity threshold is breached.
How Does a Glass Break Sensor Work?
To understand how glass break detectors work, it is best to know its two types: acoustic and shock. Each type of sensor works differently but has the same use: to set off your alarm when the glass has been broken. Acoustic glass break sensors work by hearing the sound of breaking windows, while shock sensors feel the physical disruption of broken glass.
Acoustic Glass Break Sensors
When a glass is broken and shatters, it creates a particular sound frequency. By hearing this frequency, an acoustic glass break sensor triggers an alarm, notifying the homeowner. This is why a single sensor can cover different windows and glass doors in a single room.
Shock Glass Break Sensors
Shock glass sensors don’t rely on any sound frequency. Instead, it feels the unique vibration of shattering glass. It should be physically attached to the window or door it is protecting to function properly.
While shock glass break sensors are popular to trigger less false alarm than acoustic ones, they also have some disadvantages. If you opt-in to use this sensor, you will need to install it on each window you want to monitor. This isn’t really cheap, plus it can be a pain to set up each sensor.
Advanced Features of Top Glass Break Sensors
There are several cheap glass break sensors in the market but they’re usually not the best choice to protect intrusion into your home. Here are some facts and features about top glass break sensors in the market:
- Cheaper options that use narrowband microphone are prone to false alarms
- Broadband microphones can analyze sounds on more than one level, which can result in accurate and better monitoring.
- Microphones with a microprocessor can analyze the intensity, frequency, and timing of a glass break sound and can even detect soft breaks which can sometimes go undetected. This is usually a more secure option and produces the least false alarms.
- Long-range sensors can protect glass up to 3 feet away.
- Installing it on the ceiling can decrease the chance of the signal being obstructed by barriers such as furniture.
- Indicators for low battery and sensor testing must always be visible.
- Glass break sensors should consume less energy for extended sensor life.
Are There Any Cons To Glass Break Detectors?
Since glass break detectors rely on sound frequency or vibrations, they can be too sensitive. Simpler models are designed to pick up sounds above a particular frequency, meaning they can pick up other high-frequency sounds and vibrations including accidentally breaking a glass bottle. If you feel like you will be making a lot of loud noises, such as playing musical instruments, be sure to deactivate the glass break detector before or you’re not near one.
To make sure you won’t get any false alarms, you need to get the settings right. Most of these devices have test functions, which allows you to adjust the frequency and test whether a certain sound can trigger it.
Do You Need Glass Break Detectors?
Are you looking to put up comprehensive home security? If yes, a glass break detector can be a good addition to your system. These devices are not very expensive, and will surely add an extra layer of security to protect your home.