Polynomial conversion
Combining the
Soil calibration
and
Profile Probe response
steps,
the conversion equation becomes:
3
-3
m
.
m
1
0
6
5
4
3
2
]
53
.
121
68
.
356
56
.
413
42
.
234
17
.
67
53
.
5
125
.
1
[
a
a
V
V
V
V
V
V
V
−
+
−
+
−
+
−
=
θ
where
a
and
a
are the calibration coefficients above.
0
1
For a generalised mineral soil this becomes:
3
-3
6
5
4
3
2
min
47
.
14
46
.
42
23
.
49
91
.
27
00
.
8
66
.
0
057
.
0
V
V
V
V
V
V
+
−
+
−
+
−
−
=
θ
m
.
m
,
And for an organic soil:
3
-3
6
5
4
3
2
78
.
15
32
.
46
71
.
53
44
.
30
72
.
8
72
.
0
023
.
0
V
V
V
V
V
V
org
+
−
+
−
+
−
−
=
θ
m
.
m
.
Slope and offset conversion
Combining the
Soil calibration
and linear
Profile Probe response
equations:
[
]
1
0
43
.
4
37
.
0
a
a
V
V
−
+
≈
θ
3
-3
3
-3
m
,
up to 0.3 m
.
m
.
m .
Using the values of
a
and
a
0
1
for generalised mineral and organic
soils:
From probe V to:
Slope
Offset
m
3
.m
-3
/ V
m
3
.m
-3
3
m .m
-3
0.528 -0.146
, Mineral soil
3
m .m
-3
0.575 -0.121
, Organic soil
To convert data readings from volts, multiply by the slope and
add the offset. This gives readings in m
3
.m
-3
.
Linearisation table conversion
The following table of values is used for the DL2e logger sensor
codes P2M, P2O, P2C, P2D.
20
z
Operation
Profile Probe User Manual
3.0a
