an electrically supervised detector circuit, cutting, breaking, or
grounding of gridwire shall initiate an alarm. Install gridwire in
a pattern of 100 mm 4 inches on center over a wall, door, or
ceiling area generally not exceeding 1200 by 2400 mm 4 by 8 feet
in dimensions, for each terminal strip. Cover grid pattern by a
cosmetic material such as paneling. Hard-drawn gridwire used in
fabricating security sensors shall not exceed 17.8 N 4 pounds
tensile strength and shall be capable of carrying a current of 60
milliamperes at 60 volts with a temperature rise of not more than
one degree C 2 degrees F. Wire shall not be larger than 26 AWG.
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NOTE: Utility inlet openings are protected in a
variety of methods, the correct one being dependent
on two variables: the nature of the intrusion
threat (i.e., physical penetration, electrical,
electro-optical, etc.) and the characteristics of
the utility inlet opening (i.e., discharge water
from a nuclear plant, office air duct, electric
conduit, etc.). Subsequent to such analysis, almost
any of the intrusion detection sensors described
herein could provide the necessary protection.
Normally a breakwire trap sensor is used for this
application.
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(3) Protection of utility inlet openings: Provide protection by
a sensor of the [breakwire] [wire trap] type consisting of up to
26 AWG hard-drawn copper wire with a tensile strength of 17.8 N 4
pounds maximum interlaced throughout the opening such that no
opening between wires shall be larger than 100 mm 4 inches on
center. Terminate sensor so that attempts to cut the wire or
otherwise enlarge openings between wires shall cause an alarm.
Sensor termination shall be [concealed] [tamper protected].
2.4.14.2
Interior Volumetric Sensors
a.
Passive infrared sensors: Sensors shall detect intruder presence
by monitoring the level of infrared energy emitted by objects
within a protected zone. Sensor shall initiate an alarm upon
observing increased or fluctuating infrared energy caused by the
presence and motion of an intruder whose temperature is as little
as 1 1/2 degrees C 3 degrees F different from the background
temperature. Sensor shall be passive in nature; no transmitted
energy shall be required for detection. Sensor shall be sensitive
to infrared energy emitted at wavelengths corresponding to human
body and other objects at ambient temperatures. Sensor detection
pattern shall be 3.14 rad 180 degrees for volumetric units, unless
otherwise indicated [, and shall be housed in a tamper-alarmed
enclosure]. Sensor shall provide some means of indicating an
alarm condition during installation and calibration. A means of
disabling the indication shall be provided within the sensor
enclosure. Sensor shall alarm when an intruder moves within the
area of protection more than 1500 mm 5 feet at a velocity of 30 mm
0.1 foot per second, and one step per second, assuming 150 mm 6
inchesper step. Detection sensitivity shall be irrespective of
direction of motion. Sensor shall also alarm at velocities faster
than 30 mm 0.1 foot per second, up to 3000 mm 10 feetper second.
Sensor maximum detection range shall be [a minimum of 10.6 meters
SECTION 13703N
Page 30
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