© 2015 Radiodetection Ltd
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The sonde radiates a Peak field from the center of its
axis with a ghost signal at each end of the Peak. Move
the locator a little way behind and then in front of the axis
of the sonde to detect the ghost signals. Finding the two
ghost signals positively confirms the locate. Reduce the
locator sensitivity to lose the ghost signals but still
indicate a clear Peak response directly over the sonde.
Locator sensitivity is now set for tracing the duct or drain
unless the distance between sonde and locator
changes.
Propel the sonde three paces along the drain or duct and
stop. Place the locator over the supposed position of the
sonde. Do not adjust the sensitivity level.
Figure 8.8 Sonde deployment
To locate a sonde:
1 Move the locator backwards and forwards and stop
when the bar graph indicates a Peak. You can use
the LCD compass to orient the blade of the locator
with the direction of the sonde.
2 Rotate the locator as if the blade is a pivot. Stop
when the bar graph indicates a Peak.
Figure 8.9 Locating a sonde
3 Move the locator from side to side until the bar graph
indicates a Peak.
4 Repeat 1, 2 and 3 with the antenna vertical and
resting on or just above the ground. The locator
should then be directly above the sonde with the
antenna in line with it. Mark the position of the sonde
and its direction.
5 Propel the sonde a further 1 or 2 meters, pinpoint,
and mark the position. Repeat this pinpoint
procedure at similar intervals along the line of the
drain or duct until the survey is completed.
Checking sonde depth
The RD8100 locator will automatically display the depth
of a located sonde providing the locator is correctly
oriented and positioned above the sonde. Using the LCD
compass as a guide, rotate the locator until the compass
indicates the sonde is in East / West position.
Figure 8.10: Calculating sonde depth
Calculation method
Pinpoint the sonde. Move the locator in front of the sonde
and still with the antenna in line with it, increase
sensitivity to find the Peak of the ghost signal. Move the
locator to behind the sonde ensuring that the locator
blade is always in line with the sonde. Find the null
positions A and B (See Figure 8.10). Measure the
distance between them and multiply by 0.7 to give an
approximate depth measurement.
Flexitrace
The Flexitrace is a traceable plastic covered fiberglass
rod incorporating wire conductors and is used for
locating small diameter, non-metallic pipes to a depth of
3 meters. The Flexitrace can be inserted into a pipe or
duct as small as 9 mm /
3/8” internal diameter, and ith a
minimum bend radius of 250mm. Batteries are not
required, as the FlexiTrace is powered by any
Radiodetection transmitter.
The FlexiTrace has a maximum power rating of 1W.
When using the FlexiTrace with a Radiodetection Tx-5
or Tx-10 transmitter the output limit must be set to 1W in
the MAX P menu and the output voltage limit set to LOW
in the MAX V menu.
No settings are required for the Tx-1 transmitter.
