element without causing damage to the pane of glass.
2.6.3
Glass Break Sensor, Acoustic
The glass break sensor shall detect high frequency vibrations generated by
the breaking of glass while ignoring all other mechanical vibrations. An
alarm signal shall be transmitted upon detecting such frequencies to the
alarm annunciation system.
2.6.3.1
Sensor Element, Acoustic
The sensor element shall be a microprocessor based digital device. The
sensor shall detect breakage of plate, laminated, tempered, and wired glass
while rejecting common causes of nuisance alarms. The detection pattern of
the sensor element shall be a range of 7.5 m 25 feet minimum. The sensor
element shall be equipped with a light emitting diode (LED) activation
indicator. The activation indicator shall light when the sensor responds
to the high frequencies associated with breaking glass. The LED shall be
held on until it is turned off manually at the sensor signal processor or
by command from the alarm annunciation system.
2.6.3.2
Sensor Signal Processor, Acoustic
The sensor signal processor shall process the signals from the sensor
element and provide the alarm signal to the alarm annunciation system. The
sensitivity of the sensor shall be adjustable by controls within the sensor
signal processor. The controls shall not be accessible when the sensor
signal processor housing is in place. The sensor signal processor may be
integral with the sensor or may be a separate assembly.
2.6.3.3
Glass Break Simulator, Acoustic
The contractor shall provide a device that can simulate breaking glass to
the sensor. The device shall be rated for use with the specific sensor
selected. The simulator shall not cause damage to the pane of glass.
2.6.4
Duress Alarm Switches
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NOTE: The designer will show type and location of
duress alarm switches.
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Duress alarm switches shall provide the means for an individual to covertly
notify the alarm annunciation system that a duress situation exists.
2.6.4.1
Footrail
Footrail duress alarms shall be designed to be foot activated and floor
mounted. No visible or audible alarm or noise shall emanate from the
switch when activated. The switch housing shall shroud the activating
lever to prevent accidental activation. Switches shall be rated for a
minimum lifetime of 50,000 operations.
2.6.4.2
Push-button
Latching push-button duress alarm switches shall be designed to be
activated by depressing a push-button located on the duress switch housing.
No visible or audible alarm or noise shall emanate from the switch. The
SECTION 13720A
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