HT instruments HT5000 - Manual (Page 10)

HT-5000
EN - 9
Application Principle of coupling
Single-wire lines or pipes (with
or without insulation against
earthing)
The distance between the earth
spike and the ends of the
connected lines should be as great
as possible
There is a danger of the return
current flowing through the
earth into adjacent lines, which
could result in their path being
follow
Single-wire cable with metallic
screen and earthing insulation
Short circuit between internal
conductor and screen at the end of
the cable with earthing at the
beginning and end of the cable as
well
If the earth connections made
are unfavourable, the current
in the internal conductor and
the return current in the screen
will cancel each other out.
Under certain circumstances
this can prevent the cable from
being detected. Alternatively, a
connection without an earth
connection can also be made
Multiple-wire cable (internal
conductor connected or
disconnected) with metallic
screen and earthing insulation
verso terra
Same application as in example 1
Metallic conduit (with or without
insulation against earthing)
The earth spike and the conduit
should be spaced as far apart as
possible. Under certain
circumstances, optimum
positioning of the earth spike may
require several attempts
If a return wire is available
The spacing of the return wire
should correspond to at least
10 times the depth of the line being
located
Pair of wires (with or without
screen) with short circuit at the
end of the cable
Adjacent conductors
horizontal Ö
Minimum of the reception
signal
vertically Ö
Maximum of the reception
signal