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9 LINE LOCATING
To start locating:
There are three different methods of applying the signal to the conductor with the transmitter
– Direct Connection, Inductive, and Inductive Coupling (Metroclamp). A description of each
method and use instructions follow below.
In addition to three different methods of inducing the signal onto the conductor, there are two
methods - PEAK and NULL by which to locate your conductor.
The PEAK method is generally used to follow the path or direction of a line. It is the
preferred method for general locating because the sensitivity or gain can be kept to a
minimum which prevents bleed-off onto nearby lines.
The NULL method is used for more accurate locating of the centerline of a conductor. You
would want to get an accurate locate of a conductor centerline before determining the depth
of a conductor.
PEAK and NULL procedures are described below.
9.1 Direct (Conductive) Connection
This is the preferred mode of operation because the Transmitter is connected directly to a
metallic part of the conductor (hydrant, meter, riser, valves, sheath, tracer wire) allowing a
strong maximum signal to reach the conductor. In this operating mode the Receiver can be
closer to the Transmitter, and adjacent buried conductor interference is reduced.
Transmitter:
1 With the Transmitter OFF, plug the Direct Connect Cables into the jack labeled FAULT
OUTPUT on the 480B/SFL
2 Extend the BLACK lead of the Direct Connect Cable as far as possible from the
conductor, at a right angle. Look for a convenient existing ground, such as a metal street
sign. Be careful not to get close to or cross any adjacent buried conductors. If no existing
ground is available, use the ground spike as far into the Ground as possible, and attach the
BLACK lead. To improve conductivity, put water on it. See Figure 9-1.
3 Attach the RED lead of the Direct Connect Cable to an electrically clean metallic part of
the targeted conductor.
