Table of Contents
Advertisement
9 MASKING-OUT LINES
Under certain circumstances lines at lower depths can 'hide' deeper, adjacent lines, thus making it
more difficult to locate them.
In such cases, the transmission characteristics of the transmitter can be fully utilised and the lines
which have already been located can be masked out.
Line with weaker inductive
Follow the steps below in order to locate lines by masking-out adjacent lines:
Step Action
1.
Use the receiver and the transmitter to locate and pinpoint a buried line.
2.
With the receiver resting on the ground straight above the located line, have a
colleague place the transmitter on its back (see picture above) near the line path (but at
least 15 m away from the receiver).
3.
Slide the transmitter across the line until the signal strength bargraph on the receiver is
lowest, indicating that the transmitter is directly above the line which, therefore, is
masked-out.
Note that adjacent lines may not be parallel with the first line route, so sweep the
receiver around in a circle about 10 m to 15 m radius from the transmitter, with the
handle pointing towards the transmitter. Any metallic lines within 2.5 m of the
transmitter will be coupled with the transmitted signal.
4.
Continue to pinpoint and determine the direction of any buried lines.
coupling
M
-
ASKING
OUT LINES
Line with good inductive
coupling
20
18
16
R
25
Advertisement
Table of Contents
