Operating instructions
4point light 10W (V 4.58)
Page 109 of 130
G
M
L
10 Appendix
10.1 Mathematics
10.1.1 Electrode configuration
Geometry factors and calculation methods for the various electrode configurations:
Methods
Input
Formula
Schlumberger
A/2, L/2
I
U
A
A
L
*
2
2
*
2
2
−
=
Half-Schlumberger
A/2, L/2
I
U
A
A
L
*
2
2
*
2
2
2
−
=
Wenner
A
I
U
A
*
*
2
=
Dipole-Dipole
L, A
L: dipole distance
A: distance of electrodes
(
)(
)
I
U
A
n
n
n
A
L
n
*
2
1
*
+
+
=
=
Pole-Pole
A
I
U
A
*
*
2
=
Tab. 10.1: geometry factors and calculation methods
10.1.2 Phase definition
1000
*
0
90
U
U
=
Phase in mrad
10.1.3 Voltage correction
The voltage correction is mainly for internal documentation. For each frequency the
following values are saved: Offset U0, Offset U90, A, B
Definition of A and B (measurement current = 5 mA):
)
5
(
*
Re
,
0
,
0
mA
I
k
R
I
U
U
A
f
Off
ref
=
−
=
)
5
(
*
Re
,
90
,
90
mA
I
k
R
I
U
U
B
f
Off
ref
=
−
=
U
0,ref
= voltage at ADC with reference resistor, transmitter ON
