ABEM Terrameter SAS 1000 / SAS 4000
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8.2
ERIGRAPH
The software ERIGRAPH is primarily designed to facilitate graphical presentation of CVES
(2D electrical imaging) data and associated inverted model sections. The measured apparent
resistivity can be plotted as pseudosections in colour or grey scale. Inverted sections can be
plotted as continuous (smooth) plots or as rectangular blocks. 2D inversion must be carried
out using a separate inversion program, such as for example Res2dinv. Conversion from the
field data files formats OHM
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and S4K to DAT format is also built-in, as well as conversion
to model files in RHO format from the output formats INV and XYZ created by RES2DINV.
8.2.1
Data Conversion
Before displaying the field data must be converted to the DAT format used by RES2DINV.
By selecting File/Conversion/S4K->DAT in ERIGRAPH the menu below will appear, and
upon selecting a data file the data file properties will be summarised. By ticking on/off
protocols and channels different sub-sets of the data can be extracted, and it is also possible to
shift or reverse the length coordinates.
The built-in conversion routine in ERIGRAPH can automatically incorporate topography in
the DAT file, if it is saved in an ASCII file (preferably in the same directory as the OHM file
to be converted). The topography file should have the same filename as the data but with ALT
or TXT extension. The file format is as follows:
x(1)
alt(1)
x(2)
alt(2)
...
...
x(n) alt(n)
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Used by ERIC.EXE for data acquisition controlling Terrameter SAS300C and Electrode Selector ES464 from a PC.
