from the presence of a conductive body, or a body with a high
dielectric constant such as the human body, which distorts
coupling between transmitting and sensor wires. Sensor components
shall consist of one or more signal generator field wires and
mounting hardware, sensing wires, an amplifier/signal processor,
power supplies, and necessary circuitry hardware. Mounting and
support hardware shall be provided by the equipment manufacturer.
Wires shall be spring tension-mounted and provided with
end-of-line terminators to detect cutting, shorting, or breaking
of the wires. Sensor configuration shall be selected such that an
intruder cannot crawl under the bottom wire, through the wires, or
over the top wire without being detected and shall be divided into
sensor zones. Sensors shall be capable of following irregular
contours and barrier bends without degrading sensitivity below the
specified detection level. In no case shall a single sensor zone
exceed 100 meters or be long enough to significantly degrade
sensitivity. Adjacent zones shall provide continuous coverage to
avoid a dead zone. Adjacent zones shall be designed to prevent
crosstalk interference. Signal processing circuitry shall provide
filtering to distinguish nuisance alarms. Sensor configuration
shall incorporate balanced, opposed field construction to
eliminate far field noise. Exterior components shall be housed in
rugged corrosion-resistant enclosures, protected from
environmental degradation. Provide housing with tamper switches.
Interfacing between exterior units shall be carried in underground
cables. Exterior support hardware shall be stainless or
galvanized to avoid tension degradation in the physical support
system. Sense and field wires shall be stainless steel. Wire
spacing for various configurations shall follow manufacturer's
specifications. Spacing of wires shall be maintained constant
throughout each zone and shall be uniform with respect to the
ground. Signal processing equipment shall be separately mounted
such that no desensitized zones are created within the zone of
detection. Sensor sensitivity shall be adjustable. Adjustment
controls shall be inaccessible to operating personnel. With
system sensitivity controls set at approximately midrange, system
shall alarm when an intruder is within 915 mm 3 feet of a wire.
Sensitivity shall be irrespective of direction of motion, or
velocity in the range of 30 mm to 3000 mm 0.1 foot to 10 feet per
second. Sensor shall detect intruder attempts to cross potential
dead zones, such as between adjacent zones or in the vicinity of
posts with the minimum specified performance or better. Sensor
shall provide some means of indicating an alarm at the protected
perimeter to facilitate installation and calibration. Provide an
indicator disabling device within a tamperproof enclosure. Power
required shall be 120 volts ac.
d.
Taut-wire sensors: Sensors shall consist of a perimeter intrusion
detection sensor incorporated into a barbed wire security fence.
Intrusion detection shall be achieved by cutting of any single
wire or the deflecting, as by climbing, of any wire by more than
[_____]. Sensor zone shall include one or more [61] [_____]
meters [200] [_____] foot maximum sections of [2100] [_____] mm
[7] [_____] foot high parallel fence with each sector consisting
of [13] [_____] horizontal barbed wires attached to the taut-wire
fence posts, and three strands as outriggers, plus an "antiladder"
trip wire supported by rods extending from the outriggers for a
total vertical height of approximately [2440] [_____] mm [8]
[_____] feet. Displacement switches for each horizontal wire
SECTION 13703N
Page 36
Previous Page
