Exterior Fence Sensors

TM 5-6350-275-24&P

(b) Infrared Perimeter Sensor (IPS). The IPS is a pedestal mounted active infrared intrusion sensor consisting of a

transmitter and receiver in two outdoor environment post-type housings. The transmitter unit consists of multiple

infrared beam emitting transmitters. The receiver unit consists of multiple infrared beam collecting receivers. The

sensor alarms when an infrared beam between the transmitter and receiver unit is interrupted or beam modulation is

disturbed. Automatic gain control is used to adjust for gradual changes in beam intensity caused by rain, snow, fog,

or other environmental conditions. The sensor protects a minimum of 100 meters of fence line and detects intruders

crossing the detection zone.

(c) Ported Coaxial Cable Sensor (PCCS). The PCCS is a buried line sensor that detects intruders crossing a

detection zone established by transmit and receive cables buried in parallel along a perimeter. A disturbance in the

electromagnetic field between the two cables exceeding a predetermined threshold causes the sensor to alarm.

Without line amplifiers, the sensor can protect 800 meters of perimeter. With line amplifiers, it can protect up to

1600 meters of perimeter.

(d) Short Ported Coaxial Cable Sensor (SPCCS). The SPCCS operation is similar to the PCCS. The sensor

consists of two 125 meter lengths of cable pairs. In one mode of operation, individual alarm outputs are reported for

each cable pair. In another mode, both cable pairs report a single alarm output.

(5) Exterior Fence Sensors

(a) Fence Mounted Vibration Sensor (FMVS). The FMVS is a chainlink fence mounted sensor that assures

continuous detection coverage across the full span of the fence panels, including the fence post. It consists of a

sufficient number of vibration detecting transducers to detect the mechanical vibrations caused by intruders climbing,

pulling, tugging, or cutting any part of the 200 meters of fence paneling.

(b) Strain Sensitive Cable Fence Sensor (SSCFS). The SSCFS is a chainlink fence mounted sensor that assures

continuous detection coverage across the full span of the fence panels, including the fence posts and outriggers. It

consists of strain sensitive coaxial transducers of sufficient length to detect the mechanical vibrations caused by

intruders climbing, pulling, tugging, or cutting any part of 100 meters of fence line. The sensor processor can

interface with and monitor two adjacent 100 meter segments of cable.

Outdoor perimeter sensors are usually installed in specific lengths called zones or sectors. Each zone of a system

provides its own intrusion and supervision alarms. This arrangement provides precise information on the location of

any intrusion attempt.

Zone length is determined by the geography of the perimeter, the nature of potential threats, and the degree of

security desired. The greater the security requirement, the shorter the zone should be.

The SSCFS can operate with up to 1,000 feet (300 meters) of sensor cable for each zone. The maximum zone

length for an SSCFS on a standard 2 meter high fence is 1,000 feet. Shorter zone lengths can be installed, and may

be desirable to facilitate CCTV assessment of intrusion activity.

The SSCFS provides an alarm if an intruder attempts to climb over the fence, cut through the fence, lift the fence

fabric, or break through a wall, ceiling, or other mounting surface (interior installation).

The SSCFS provides a supervision alarm if there is a short in the cable or it is cut open. The alarm is also initiated

by the tamper switch if the processor cover is opened.

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