The Bosch Glassbreak Detector uses microprocessorbased sound analysis technology (SAT) to listen for the specific frequencies associated with breaking glass. A built-in environmental test feature alerts the installer to false alarm hazards in harsh environments. The round detectors mount on the ceiling or walls. Functions Signal Processing Audio signals are analyzed using microprocessor-basedSAT and must produce specific frequency, signature, and timing relationships to cause an alarm. The sophistication of this processing technique ensures proper catch performance while eliminating false alarms. Test Features The magnet‑operated test mode provides a location verification and operational test when using the optional DS1110i Glassbreak Tester. The test mode also includes an environmental test that alerts the installer to possible false alarm sources caused by ambient noise. The automatic sound check feature allows the end user to verify that the detector is powered and functioning by clapping his hands. Anexternally‑visible alarm LED indicates an alarm or test condition and can be programmed to latch if desired.