A glass break detector is a sensor used in electronic burglar alarms that detects if a pane of glass is shattered or broken. These sensors are commonly used near glass doors or glass store-front windows to detect if an intruder broke the glass and entered.
Glass break detectors usually use a microphone, which monitors any noise or vibrations coming from the glass. If the vibrations exceed a certain threshold (that is sometimes user selectable) they are analyzed by detector circuitry. Simpler detectors simply use narrowband microphones tuned to frequencies typical of glass shattering, and react to sound above certain threshold, whereas more complex designs compare the sound analysis to one or more glass-break profiles using signal transforms similar to DCT and FFT and react if both the amplitude threshold and statistically expressed similarity threshold are breached.
Read more about Glass Break Detector: Also See
Famous quotes containing the words glass and/or break:
“... this I conceive to be no time to prate of moral influences. Our men’s nerves require their accustomed narcotics and a glass of whiskey is a powerful friend in a sunstroke, and these poor fellows fall senseless on their heavy drills.”
—Clara Barton (1821–1912)
“I believe very profoundly in an over-ruling Providence, and I do not fear that any real plans can be thrown off the track. It may not be intended that I shall be President—but that would not break my heart.”
—Woodrow Wilson (1856–1924)