Line and probe location in “Ferrolux” mode
56
5.3.4
Clear identification of the line on the basis of the current flow
direction (only possible with SignalSelect-modulated signal)
If the transmitter couples a SignalSelect-modulated signal into the line that is being
located, its current flow direction can be identified with the iFS receiver and therefore the
line on which a signal is being transmitted can be clearly identified. This is particularly
useful, if several lines (cables, pipelines) are running close to each other. In these
cases, the return current often couples into the adjacent lines, since these have the
least transition resistance. Even if the signal strength is significantly lower on these
lines, the signal level received at the surface could adopt similar values in unfavourable
cases if the line on which the signal is being transmitted is laid significantly deeper than
the adjacent lines, for example.
Please read the associated operating manual for information about how
SignalSelect mode is activated at the transmitter.
A prerequisite for correct evaluation of the SignalSelect indication is knowledge of your
own orientation in relation to the signal injection point. This should generally be located
behind the user. If this is the case, the following rules apply:
•
A
is shown in the SignalSelect display above the line on which the signal is
being transmitted.
•
A
is displayed on the SignalSelect screen above all adjacent lines on which
the signal is flowing back in the direction of the connection point.
Introduction
Determining the signal
direction