abem Terrameter LS, Инструкция по эксплуатации

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ABEM Terrameter LS
45
Figure 46. Cable arrangement at the first measurement station in a roll-along
survey, where the first cable is excluded
Take-out # 21 of cable one shall overlap take-out # 1 of the next cable at the cable
joints and in the layout centre. Overlapping takeouts connect to the same electrode.
Link together the inner and outer electrode cables (Cable 3 and Cable 4 only at this
stage) with a cable joint (cylindrical connecting device). The cable joints have one
grove for 4x21 cable sets and two grooves for 4x16 cable sets. Take care to connect it
in the right direction: the groove(s) on the cable joints should point towards the
instrument in the layout centre (Figure 47).
Instrument O uter end
Instrument Outer end
Figure 47. Cable joints with connection direction for, a) 4 x 21 take-out cable set,
b) 4 x 16 take-out cable set
Connect electrodes to the odd-numbered take-outs on all active electrode cables. The
even-numbered take-outs can be left out for the time being. If the ground is soft and
moist the electrodes can just be pushed into the ground and connected, however
hammering and wetting is often needed. Check the contact surfaces between electrode
take-outs, cable jumpers and electrodes for dirt and oxide, which can ruin the data
quality, and clean if needed. Link together inner and outer electrode cables using the
white cable joints. Connect the Terrameter LS at the centre of the cable spread, that is
between cable #2 and cable #3. Turn on the instrument and follow the steps described
in Section 3 “Instrument and Data Acquisition Setup”
At the second measurement station, and all the following stations as long as the line is
being extended, all four cables are connected (see Figure 48). Cable 1 is connected to
Cable 2 with a cable joint as well, where again the groove must face the cable closest
to the instrument.
Figure 48. Cable arrangement at the second measurement station in a roll-along
survey
When finishing the measurement profile, and no additional electrode cable and
electrodes are put out, the instrument should still be moved one step in order to get all
the near surface information. The active electrode cables will thus be Cable 1, Cable 2
and Cable 3 (see Figure 49). Since all possible measurements have already been done
for the long layout protocol the measuring will be fast.