Acoustic Emission in Alarm Applications

Abstract: This thesis, issued by Securitas Direct, investigates the possibility of using acoustic emission as a basis for an intrusion alarm application. Piezoelectric elements were used to detect and characterize fractures in glass, metal and wooden materials. As a comparative study, the functionality and possibilities of using an existing glass break detector, GlassAlertTM, on wooden materials were investigated. The work was performed on selected specimens of wood and glass in a laboratory environment. The results conclude that, possibly with some software modfications, GlassAlertTMcould be used as a reliable glass break detector but even with hardware changes it could prove difficult detecting fractures in wood. It is on the other hand most possible to use the piezoelectric element on different materials by implementing different software in the detector structure. However, the work with piezoelectric element should be further examined before concluding that it can really be a product suited for the market.