GENERAL DESCRIPTION
GENERAL DESCRIPTION
The GEM-GB is an advanced wireless acoustic glass-break detector for
use with all Gemini-Series control panels and receivers. Each transmitter
has a unique RF ID code (printed on the sensor module and on the rear
case) that distinguishes itself to the receiver. Refer to control-panel instruc-
tions for entering this code and its checksum digit into the panel. Be sure
to enter all numbers and/or letters, including leading zeros, if any.
The detector is powered by two type DL123A 3-volt lithium batteries,
which are factory installed. To energize the unit, simply install the supplied
Power-Up Jumper across pins JP1 near the positive terminals of the
batteries.
SPECIFICATIONS
SPECIFICATIONS
Microphone:
Microphone: Electret, omnidirectional
Temperature Range:
Temperature Range: 32°F to 120°F (0°C to + 50°C)
Range of Coverage
Range of Coverage (radius distance from sensor)::
Plate Glass, 25’ (7.6m)
Tempered, Wired, or Laminated Glass, 20’ (6m)
Note:
Note: (1) Use 20’ (6m) radius if unsure of glass type. (2) If not using a
Sentrol 5709-C Tester to verify range, reduce range to 15’ (4.5m) for
windows with blinds or unlined drapes. (3) Reduce coverage 50% for
armor-coated glass.
Glass Thickness:
Glass Thickness:
Plate Glass,
3
⁄
32
to
1
⁄
4
’’ (2.4 to 6.4mm)
Tempered Glass,
1
⁄
8
to
1
⁄
4
’’ (3.2 to 6.4mm)
Wired Glass,
1
⁄
4
’’ (6.4mm)
Laminated Glass,
1
⁄
8
to
1
⁄
4
’’ (3.2 to 6.4mm)
Dimensions:
Dimensions: 3.13 x 4.24 x 1.7’’ (8.0 x 10.8 x 4.3cm) (h x w x d)
Shipping Weight:
Shipping Weight: 7.5oz (213gm)
FEATURES
FEATURES
•
Superior immunity to false alarms
•
Excellent detection, even through blinds and light drapes
•
25’ radius
•
Automatic test for easy installation
•
‘‘Hand-clap’’ test for sensor verification
•
Includes lithium batteries
MOUNTING
MOUNTING
Note:
Note: The GEM-GB may be mounted in any position with no degradation
in performance. However, for reference purposes in this text, the unit will
be considered oriented with the antenna at the right, as shown above.
The detector mounts with two #6 screws (supplied). The rear case may
be used as a template to mark mounting holes on the wall.
The sensor must be in direct line of sight of all windows being protected.
Reliable detection cannot be expected around corners, in other rooms, etc.
For optimum false-alarm immunity, avoid installing the unit
•
in rooms with lined, insulating, or sound-deadening drapes;
•
in rooms with closed wooden window shutters inside;
•
in rooms smaller than 10’ x 10’ (3m x 3m), and in rooms with multiple
sounds, such as kitchens, glass booths, noisy areas, garages, etc.
•
within 4’ (1.2m) of noise sources such as televisions, speakers, sinks,
doors, etc.
•
on ceilings higher than 15’ (4.5m), if mounting on ceiling;
•
on 24-hour loop applications (perimeter loop okay);
•
where white noise (such as air compressor noise) is present. (May cause
false alarms by saturating glass-break frequency spectrum.)
Wall Mounting
Wall Mounting
Since the sound of breaking glass travels outward from the source, the
best location for the GEM-GB detector is on the wall opposite the windows
being protected (assuming, of course, that the wall is within the sensor’s
range). Detection is reduced with same-wall mounting since such detection
is partially dependent upon sound reflected off the opposite wall.
Ceiling Mounting
Ceiling Mounting
Similarly, a ceiling-mounted sensor will detect better if mounted 6’ to 10’
(2--3m) away from the glass, rather than directly above it. Mount the
detector on any type of ceiling in direct line of sight of the windows being
protected, at least 1’ (0.3m) and preferably 3’ (1m) from the glass.
Installation Notes
Installation Notes
1. The GEM-GB is designed to detect the shattering of framed glass
mounted in an outside wall. Testing the sensor with unframed glass,
broken bottles, etc. may not trip the sensor. The GEM-GB typically does
not trip to glass-break tests in the middle of a room, as such breaks are
false alarms.
2. False alarms are most likely to occur when installed on a 24-hour loop
in glass airlocks and glass vestibule areas, when mounted above sinks,
when used in residential car garages, and in other small, acoustically live
rooms and rooms where multiple sound can reflect and eventually dupli-
cate the glass-break frequency pattern. For occupied-area glass-break
protection in such applications, the use of shock sensors is recommended.
3. Installing the GEM-GB on 24-hour loops will increase false alarms. The
GEM-GB is recommended for perimeter loops and is designed to function
without false alarms in occupied areas. On a 24-hour loop, which is armed
all day, all night, every day, the false alarm technology will be pushed to
its limit since some sounds in some conditions can duplicate the points on
the glass-break pattern that the GEM-GB detects. Install the GEM-GB on a
perimeter loop, which is armed whenever the door and window contacts
are armed. For occupied-area installations, the GEM-GB’s false-alarm
immunity is best in rooms with only moderate noise.
4. The GEM-GB detects the shattering of glass. As with all glass-break
detectors, it may not consistently detect cracks in glass or bullets that break
through the glass or break out the glass. Glass-break detectors should
always be backed up by interior protection.
TESTING
TESTING
Preliminary
Preliminary
Use a Sentrol Model 5709-C hand-held tester (available separately) to
place the GEM-GB detector into its test mode and for all functional testing.
Set the tester for tempered glass. Holding the tester speaker directly over
NAPCO
NAPCO
GEM-GB
GEM-GB
Wireless Glass-Break
Wireless Glass-Break
Detector
Detector
© NAPCO 1996
WI816A 3/96
Fig. 2. Typical coverage pattern for wall-mounted units.
Fig. 2. Typical coverage pattern for wall-mounted units.
Fig. 1. GEM-GB detector, cover removed.
Fig. 1. GEM-GB detector, cover removed.
Fig. 3. Typical coverage pattern for ceiling-mounted units.
Fig. 3. Typical coverage pattern for ceiling-mounted units.
