Break sensors

 

— security sensors that react to glass breaking.

Nowadays, such sensors are most often made contactless and do not require placement on the glass itself, although there are exceptions. And the most popular principle of their work is acoustic: with the help of a microphone, the sensor “listens” to the environment and reacts to the sound of breaking glass (this sound is quite unique, it is easy to separate it from extraneous noise). There are other principles of operation, for example, infrared (reaction to a sharp change in the visible "picture") or vibration (tracking shocks and vibrations using a contact sensor). Some models also have the functionality of a motion sensor, and sometimes a full-fledged vibration sensor.