Radiodetection spx RD8200 Operation Manual Download

Page: 29 / 68

Set the locator sensitivity to approximately 50% by

pressing the

key

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.

If using Peak+ mode, switch to null arrows by pressing

and holding the

key. Alternatively switch to Null

antenna mode.

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 the 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.

5.7 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.

Passive sweep

A passive sweep is used to locate Power, Radio, CATV
or CPS signals that may radiate from buried conductors.

To perform a passive sweep:

1 Press the

key to select the passive frequency you

wish to locate. You can select from the following
passive frequencies:



Power



Radio



CATV (Cable TV)



CPS (Cathodic Protection System)



PASSIV (simultaneously detects Power and
Radio signals where present)

2 Adjust the sensitivity to maximum; reduce the

sensitivity to keep the bar graph on scale when there
is a response.

3 Traverse the area in a grid search, at a steady walk,

and hold the locator comfortably with the antenna in
line with the direction of movement and at right
angles to any lines that may be crossed.

Figure 5.4: Passive sweep

Stop when the locator response rises to indicate the
presence of a line. Pinpoint the line and mark its
position. Trace the line out of the area being searched.
Resume grid search in the area.

In some areas there may be a confusing amount of 50 /
60Hz power signals. Lift the locator 50mm

/ 2” from the

ground and continue the sweep, or use the

key to

switch from Power mode and use Power Filters to
discriminate individual lines.

Switch the locator to Radio Mode. Increase sensitivity to
maximum and repeat the above grid search procedure
over the area. Pinpoint, mark, and trace out any lines
that are located.

In most, but not all areas, radio mode will locate lines
that do not radiate power signals and a grid search

should be made in both power and radio modes or in
Passive Avoidance mode.

Figure 5.3: Pinpointing with Peak and Null indicators

Figure 5.2: Pinpointing a target line