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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 RD8200 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 12.12: 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 with
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.
WARNING! Failure to follow the Tx-5 or Tx-10
instructions above may result in the tip of the FlexiTrace
becoming too hot to touch, resulting in risk of personal injury
and damage to the equipment.
The FlexiTrace can be used in two modes: Sonde mode
or Line mode. In sonde mode only the tip of the
FlexiTrace is energized whilst in line mode its whole
length is energized.
To use as a sonde, connect both transmitter leads to the
FlexiTrace stud terminals. As the FlexiTrace terminals
are not color coded it does not matter to which terminals
the leads are connected. To use the FlexiTrace in line
mode, connect the red transmitter lead to one of the
FlexiTrace terminals and connect the black transmitter
lead to a suitable ground connection.
12.7 Stethoscopes
When to use a stethoscope
At times, it may not be possible to put a clamp around a
cable
because
of
congestion
or
because
of
inaccessibility. A stethoscope antenna should be used in
place of a clamp to identify the target cable(s).
How to use a stethoscope
Plug the stethoscope into the locator accessory socket.
Press the concave head against each cable in turn to
detect a maximum signal.
Stethoscope range
Large stethoscope antenna
The large stethoscope antenna, which plugs into the
locator accessory socket, is used for cable identification
in situations where the cable is exposed. It is particularly
useful for identifying heavy cables lying in a tray where
it is not possible to fit a clamp. The concave detector
head on the end of the insulated, flexible gooseneck is
placed firmly against the cable to be identified. If there
are a number of cables, the stethoscope antenna will
give the strongest response from the cable to which the
transmitter signal has been applied.
40mm
Figure 12.13: FlexiTrace
8mm
40mm
