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8.2 Faults Under Pavement
Faults under pavement or other slightly conductive surfaces can be found using the foam pads
supplied with the unit. Saturate the pads with water and insert the A-Frame spikes into the
pads. Locate the fault as you normally would. Be sure to keep the pads as moist as possible,
but do not let the water form a continuous puddle between the pads as this will short out the
signal.
8.3 Long Distance Tracing.
As the distance to the fault increases, the signal picked up by the A-Frame is proportionally
reduced. This condition can lead to problems if the signal levels are reduced to the point that
they can no longer be detected by the A-Frame.
Whenever working with weak signals due to long distance faults (or other reasons), increased
sensitivity can be obtained by extending the distance between the A-Frame spikes using the
extension cable. This extension method can be applied to any of the previously discussed
methods including the conductive foam pads. When working with very long distances, as in
fiber optic runs, the sensitivity can be increased even further using a longer insulated wire to
extend the A-Frame span. See
Figure 8-4
.
Figure 8-4: Fault Location Using Extension Cable for Increased Sensitivity
