UFC 3-570-06
JANUARY 31 2003
Figure 7-15. Testing for a Shorted Dielectric Using a Pipe Locator
Sig na l
T est St at io n or
Pipe Lo ca to r
M eta llic C on ta ct
(if requ ired)
Sig na l
G en erat or
Sig na l
7-7.3.1
The Pipe Horn, Model FDAC200, detects the signal from a single-phase
rectifier. With the impressed current system on, this locator can be used to follow the
underground pipeline. If a dielectric is shorted, and the current is sufficient, the locator
will follow the signal across the dielectric. Consequently, if the signal is followed
through the dielectric, that dielectric is bad. If no signal can be followed, verify with the
insulated flange tester (paragraph 7-7.2).
7-7.3.2
A short wave length pipe locator, using a direct connection, detects the signal
from a signal generator. To obtain a strong signal, ensure that a good metallic
connection is made, a good battery is installed in the signal generator, and most
importantly, that the signal generator has a good, low resistant ground. This locator can
then be used to follow the underground pipeline. If a dielectric is shorted, and the signal
is sufficient, the locator will follow the signal across the dielectric. Consequently, if the
signal is followed through the dielectric, that dielectric is bad. If no signal can be
followed, verify with the insulated flange tester (paragraph 7-7.2).
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