Window Functional Design Specifications :
A perimeter security system must include a glass protection system because magnetic switches do not protect against an intruder entering through a broken window. Glass protection systems are available in two categories: vibration and acoustical.
The vibration system is mounted on the glass or on a nearby wall and detects movement of the glass. Acoustical systems, or sound discriminators, sense the sound of breaking glass. The unit can be tuned to react only to the specific frequency of glass breaking, typically 4KHz–6KHz, or it can react to any loud noise.
Some manufacturers have combined vibration and sound detectors into one unit that does not activate unless both are detected.
These units can be used where the normal conditions would cause a single technology detector to generate false alarms.
Post a Comment