Radiodetection rd7000+, Operation Manual

Page: 41 / 53

© 2014 Radiodetection Ltd 34
Figure 9.2: Locating faults with the locator and A-frame
Take readings at the survey intervals determined by the
reference reading. To locate the cable or pipe while using
the fault find signal during a Fault-Find survey, press the
key once and the locator will switch to peak locate
mode. To use alternative antenna modes, press the
key to step through available antenna modes. To get
back to fault find mode step through all available
antenna modes until the locator goes back to fault find
mode.
Note: While the A-Frame is connected to the locator,
depth and current measurements will not be available. If
depth or current measurements are required, remove
the A-Frame lead from the locator.
As a fault is approached the Fault-Find direction arrow
will lock on to the fault signal, point forward and the dB
readings will increase. When the fault is passed the
arrow will point back towards the transmitter. Take
readings at smaller survey intervals to determine the
exact point of the fault.
When the A-frame is directly over the fault the dB
reading will drop as shown opposite.
NOTE: The values given are for illustration purposes
only and may not be the same as those obtained in
other situations.
To pinpoint the fault, turn the A-frame 90° to the cable
or pipe and Fault-Find until the exact point is found.
Where the arrow direction changes the center line of the
A-frame is now directly over the fault.
Mark the ground to show the position of the fault. Find
the maximum dB reading in front of the fault by pushing
the A-frame into the ground at small intervals. Note the
dB reading. If the reading is approximately the same as
the reference reading, you can assume that there is
only one fault. If the reading is less than the reference
reading, keep surveying the cable for other faults.
NOTE: If the cable or pipe runs under a road, use the
equipment as normal on the road surface as it can
sometimes detect signals when working on blacktop,
concrete, or paved surfaces. If necessary, try wetting
the road surface. Pouring a very small amount of water
around the bottom of the A-frame spikes before each
Fault-Find will generally ensure a good ground
connection.
NOTE: If the cable or pipe runs under a paved surface,
the fault can often be pinpointed by fault finding in the
grass/soil adjacent to the paving. Reduce the distance
between placing the A-frame spikes in the ground to
allow for the increased distance to the actual fault
position.
Section 10 - Survey Measurements
locator models are capable of transmitting
survey measurements to an external device running a
compatible software application. When a measurement
is taken, the locator will transmit the most
relevant measurements take and info data, such as:

Log number

Current

Gain

Depth

Signal

Phase

Frequency

Marker type
These measurements, taken at specific points indicated
by you, can be used to report and map all your findings.
If the locator is paired to Pocket PC (or PDA ) with GPS,
running a compatible application such as SurveyCERT
(see section 11.3) the locator will append position and
time information to the data.
Refer to Section 11 - for more information about
Bluetooth pairing.