Geonics Limited EM31-SH, Operating Manual

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EM31-SH MANUAL Page
24
Figure 3: Typical Response over a pipe
4.0 SURVEY
TECHNIQUE (cont’d)
It should be remembered that the EM31 is an electromagnetic
tool and care should be taken near obvious conductors until
the operator has satisfied himself as to their possible
effect. In every case this is determined by rotating the
instrument and determining whether there is maximum and
minimum which appears to be related to the structure. If a
structure is giving such an effect it is not advisable to
take the average value of the two readings as in an indicator
of the terrain conductivity.
DISTANCE D IS
OF THE ORDER
OF
3
M.