ABEM Terrameter SAS 1000 / SAS 4000
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3.4.4
Induced Polarization surveys
It is preferable to use non-polarisable electrodes for the potential electrodes. However,
stainless steel electrodes will work fine in many cases, even though the noise level is
increased considerably. For IP soundings perform as described above in section 3.4.3, with
the exception that you have to select IP mode instead of Resistivity.
It is preferable to use the AUTO setting for the output current. In IP surveys it is very
important to eject as high current as possible. The chargeability can be measured in up to 10
time windows staring from 10 msec and upward (in steps of 20 msec), with a total duration of
the measurement interval of 8 seconds. A general and convenient setting for the first time
window is from 10 msec to 110 msec. Please see section 2.4.2 (page 6) for further
information on how the chargeability is measured.
The IP readings are displayed in a window
similar to the one used for display of
resistivity
results.
The
unit
for
the
chargeability is ms (milliseconds).
Ch P1 P2 Chargeability S.Dev Stk .
1: 0 0 12.14 ms 1.2 4 .
2: N/A .
3: N/A .
4: N/A .
N=2 I=Auto .
Resistivity: Untitled, Untitled .
I00017.S4K C1= , C2= .
When measuring in IP mode also the
resistivity is measured automatically. By
activating the knob (downwards) the detailed
information is displayed. Proceed with the
knob to display the results for channels
2-4 (if measured).
Mode: IP I=200 mA
Rec: I00017.S4K V=42.11 V
Channel: 1 R=210.55
M=12.14 ms
S.Dev.=1.2
Stks=4
Activating the
again brings up detailed
information about the decay voltages for each
channel. The primary voltage is given in the
first row. The decay voltages for up to six
time windows are given in the following
rows.
Ch.#1 Ch.#2 Ch.#3 Ch.#4
42.11 V --- --- ---
8.20 mV --- --- ---
2.44 mV --- --- ---
--- --- --- ---
--- --- --- ---
--- --- --- ---
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