HT instruments HT5000 - Manual (Page 13)

HT-5000
EN - 12
Under certain circumstances lines at lower depths can 'hide' deeper, adjacent lines, thus
making it more difficult to locate them.
In such cases, the transmission characteristics of the transmitter TX5000 can be fully
utilised and the lines which have already been located can be masked out (see Fig. 8)
Fig. 8: Masking-out lines
Follow the steps listed below in order to locate lines by masking-out adjacent lines
Step Action
1
Use the RX5000 and TX5000 to locate and pinpoint a buried line (see
paragraph 4.3.2)
2
With the RX5000 rested on the ground straight above the located
line, ask a colleague to place the TX5000 on its back (see Fig. 8)
nearby the line path (at least 15m away from the receiver)
3
Slide the TX5000 across the line until the signal strength bargraph is
lowest, indicating that the transmitter is directly above the line which,
thus, is masked-out
Note that adjacent lines may not be parallel with the first cable
route, so sweep the receiver around in a circle about 10m - 15m
radius from the transmitter, with the handle pointing towards the
transmitter. Any metallic lines within 2.5m of the transmitter will be
coupled with the transmitted signal
4
Pinpoint and determine the direction of any buried lines (see
paragraph 4.3.1.2)
Line with weaker
inductive coupling
Line with good
inductive coupling