Radiodetection rd7000+, Руководство по эксплуатации

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© 2014 Radiodetection Ltd 17
This mode is only available for the PLM and TLM
models.
1 Press the key until the null mode icon is
displayed on the LCD
4.3 Compass
The LCD compass provides a visual indication of the
direction of the target cable, pipe or sonde. The
compass is available for all frequencies apart from
Power, Radio and Passive.
4.4 Trace
Line tracing can be accelerated by switching the locator
to Null mode (PLM and TLM models only).
Move the locator left and right while walking along the
path of the line to observe the null directly over the line
and a peak response to each side of the line. As you
move the locator over the line, the left and right arrows
(and an accompanying tone) will indicate if the target
line is to the left or right of the locator.
Periodically switch to peak mode, locate the target line,
and verify its exact position.
4.5 Pinpoint
Locating a target line in peak mode accurately defines
the position of a target line after it has been traced and
its position is approximately known. Start with medium
output power from the transmitter, medium frequency on
the transmitter and locator, and peak mode on the
locator.
Set the locator sensitivity to approximately 50%.
NOTE: it may be necessary to adjust the sensitivity level
throughout the pinpointing to keep the bar graph on
scale.
1 With the antenna perpendicular to the line, make
traverses across the line. Define the point of
maximum response.
2 Without moving the locator, turn it round as if it is on
a pivot. Stop at the point of maximum response.
3 Hold the locator vertical with the antenna just above
the ground and move the locator from side to side
across the line. Stop at the point of maximum
response.
4 With the end of the antenna close to the ground,
repeat steps 2 and 3.
5 Mark the position and direction of the line.
Repeat the steps of the procedure to increase pinpoint
accuracy.
Switch to null response mode and move the locator to
find the null position. If the position of the peak and the
null pinpoints correspond, it can be assumed that the
pinpoint is accurate. The pinpoint is not precise if the
marks do not correspond, but both marks will show an
error to the same side. True line position will be close to
peak position.
The line lies half the distance to the other side of the
peak position as the distance between the peak and the
null positions.
4.6 Sweep and search
There are a number of techniques available for locating
unknown lines in an area. Using these techniques is
particularly important before conducting any excavation
work to help ensure that buried lines are not damaged.
Figure 4.2: Pinpointing a target line
Figure 4.3: Pinpointing with Peak/Null
Figure 4.1: Line Tracing