set approximately at midrange. System 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 inches per step. Sensitivity shall be
irrespective of direction of motion. Sensor shall be [installed
to be self-protecting] [housed in a tamper-alarmed enclosure].
The number of transceivers chosen shall be adequate to completely
cover the protected zone. In the event that dead spots cannot be
overcome by adding sensors, the use of a different type sensor
shall be employed. Power output from each transceiver shall be
minimum level required for stable operation and adequate
sensitivity. Maximum power density radiated from transmitters
shall not exceed 0.2 mW per square centimeter at 30 meters 100 feet.
Frequency of emissions and allowable power densities for each
shall be governed by FCC 47 CFR 15. Mount transmitters near
ceiling on vibration-free surfaces. Electronic circuitry shall be
solid state, mounted on printed circuit boards. Sensor elements
shall contain circuitry for transmitter drive, signal processing
[, tamper circuitry,] and power supplies. Circuitry shall provide
an alarm relay with contacts capable of carrying 2 amperes at 120
volts ac minimum.
e.
Audio sensors: Sensors shall consist of microphones which detect
audio information and transmit signals to an audio amplifier in a
central control unit. Multiple units may be connected to a
central control unit. Audio sensors shall be designed to be
especially sensitive to generic audio intrusion signature of
[breaking glass] [splintering wood] [fracturing of cement block]
[normal voice conversation]. Sensors shall have sensitivity
adjustments which shall be inaccessible to operating personnel.
Sensitivity adjustment shall permit operating ranges up to a
maximum of [465] [_____] square meters [5000] [_____] square feet.
Sensors shall have a detection sensitivity of [unidirectional
design] [omnidirectional design]. [Audio assessment capability
shall be provided.] Sensors shall be capable of installation in a
concealed configuration and shall be inherently self-protecting.
f.
Photoelectric sensors: Sensors shall detect intruder presence by
establishing a series of infrared or ultraviolet beams and
detecting beam disruptions. Beam transmitters shall be designed
to emit [no perceptible] light. Beam may be reflected by one or
more mirrors before being received and amplified. Disruption of
the beam by an opaque body shall initiate an alarm. Transmitted
beam shall be uniquely modulated to prohibit an intruder from
shining another light source into the receiver to escape
detection. Provide a means of local alarm indication on the sensor
for use at the protected zone during installation and calibration.
Provide with an indicator disabling device within the sensor
enclosure. Sensor shall consist of modulating transmitter,
focusing lenses, mirrors, demodulating receiver, power supply, and
interconnecting lines. House elements in tamper-alarmed
enclosure. Receiver unit shall provide an alarm relay with
contacts capable of carrying 2 amperes at 120 volts ac minimum.
Protective beam shall be focused in a straight line. Installed
beam distance from transmitter to receiver shall not exceed 80
percent of the manufacturer's maximum recommended rating. Mirrors
may be used to extend the beam or to establish a network of beams.
Each mirror used shall derate the maximum system range by no more
than 50 percent. Mirrors and photoelectric sources used in
SECTION 13703N
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