Site survey
Page 34
FiberPatrol Site Planning & Installation Guide
Deploying the sensor cable
There are two standard methods of deploying FiberPatrol sensor cable.
1.
The cable drum can be mounted on a cable stand and then the cable can be pulled around the
perimeter.
2.
The cable drum can be mounted on a reel trailer or a truck, which lays out the cable on the
ground as it moves around the perimeter.
Refer to the site plan and pull back and lay out sufficient sensor cable to cover the site specific
features (gates, bypasses, service loops, sensitivity loops, isolation loops, fiber access points).
The following factors must be considered when deploying FiberPatrol sensor cable along the
inside of the perimeter fence:
•
The length of the section of sensor cable being deployed.
•
Clearance and access along side the fence.
•
Service loops, sensitivity loops, isolation loops, splice loops, gate coverage.
•
Site-specific features such as cable bypasses for gates and other structures on the perimeter.
•
The location of splices.
Sensor cable splices
At all designated splice points, each section of sensor cable requires a 10 m (33 ft.) service loop.
The service loops at splice points allow the sensor cable and splice enclosure to be attached to,
and removed from, the fence fabric for splicing. Inside the splice tray, sensor fibers S1 and S2 and
any dark fibers that are designated for use must be fusion spliced. When dressing the bare fibers,
ensure that the turn radius is kept above a minimum bend radius of 32 mm (1.25 in.). Any tighter
bend radius may lead to optical fiber damage and an increased loss at the splice location.
Sensor cable loss limits
Once the field splices are complete, and the sensor cable is installed, the loss must be measured
from both ends of the cable to ensure the quality of each splice. The maximum loss for a single
event is 0.1 dB. The average loss for the full length of sensor cable must be 0.3 dB per km or less.
Figure 40 Perimeter structure bypass (below ground)
Note
Install FiberPatrol sensor cable on the side of the fence that is opposite
the threat (the secure side of the fence).
buried conduit
fence-mounted
isolation loop
fence-mounted
isolation loop