ABEM Terrameter SAS 1000 / SAS 4000
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14.9
GRAD1L7 + GRAD1S7: 1-CHANNEL MULTIPLE GRADIENT
ARRAY CVES WITH 4 ELECTRODE CABLES
This combination of protocol files is intended for multiple gradient array CVES roll-along
measurements, and has been found very useful for a variety of applications. It offers a
resolution superior to the commonly used Wenner array. Note that it is important to select the
protocol files in the correct order, starting with the long layout (GRAD1L7) before selecting
the protocol for short layout (GRAD1S7). It gives a dense near-surface cover, and a slightly
sparser measurement pattern at long electrode spacings. GRAD1S7is designed to supplement
GRAD1L7for the shortest electrode spacings only.
Array
type
Protocol
name
Address
file
No of
data
ORG
No of
data
UP
No of
data
DWN
Total data
for
one
layout
18
Gradient
GRAD1L7 LONG
518
245
245
1022
GRAD1S7 SHORT
224
140
140
18
Total number of data points for a four-cable layout using the procedure described in this manual.
Figure 33. Data cover of GRAD1L7 and GRAD1S7 for roll-along with three full stations
(minimum electrode spacing 5 metres). Note that many data points fall on top
of each other in multiple gradient array pseudosection plots.
