ABEM Terrameter SAS 1000 / SAS 4000
- 44 -
X axis
Y
a
x
is
Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
Line 8
Line 9
Start
End
Start
End
Start
End
Start
End
Start
End
Start
End
Start
End
Start
End
Start
End
Figure 16. Example showing a survey consisting of 9 parallel lines oriented in the
x-direction. In this case, according to the nomenclature of Res2dinv collate tool,
all lines have the same X location of first the electrode along this line, but
different Y locations. The line direction is zero in all cases (0=X,1=Y), and the
line direction/sign is also zero (0=positive,1=negative).
5.
While measuring is being carried out, electrode cable(s) can be rolled out and electrodes
connected on the next investigation line. The distance between lines should normally not
exceed twice the electrode separation.
6.
When measuring is finished on the first line, select “Quit”, disconnect the Electrode
Selector and move it and the Terrameter to the second line. Start a “New” data file and
proceed with measuring as above.
7.
Remove the cable(s) and electrodes from the first line and set up the third line. Continue
this process as far as desired.
8.
Using a separation between the lines that is equal to the electrode separation will increase
the resolution. If extra resolution is required the process can be repeated with the electrode
cables rolled out in the perpendicular direction (Y-direction).
9.
After data acquisition is completed, download all the data files to a computer using the
utility software. Convert the data files to the DAT-format used by Res2dinv.
10.
Make a copy of the file COLLATE_2D_TO_3D.TXT (can be found in the Res2dinv
program directory) and change filenames and coordinates according to the present survey.
Start Res2dinv and use the option “File/Collate data into Res3dinv format” to merge the
files.
11.
Start Res3dinv and invert the merged data file.
6.2.11
Borehole Measurements
Borehole measurements require electrode cables designed for this purpose, standard Lund
Imaging System electrode cables are not suitable. Address files must be designed to suit the