Environmental Engineering Reference
In-Depth Information
Ta b l e 4 . 1 2
Averaged Cole-Cole parameters for the ten types of vegetable oil (at 20.0
◦
C).
Standard deviation values are also reported
type of oil
ε
s
σ
ε
s
ε
∞
σ
ε
∞
f
r
σ
f
r
β
σ
β
(MHz)
(MHz)
olive (ac.=0.3%)
3.08
0.01
2.39
0.01
315
11
0.33
0.01
olive (ac.=1.2%)
3.14
0.01
2.38
0.01
288
9
0.36
0.02
olive (ac.=1.6%)
3.19
0.03
2.36
0.01
259
4
0.40
0.01
olive (ac.=4.0%)
3.19
0.03
2.34
0.02
249
5
0.42
0.02
peanut
3.05
0.01
2.40
0.01
334
5
0.28
0.01
sunflower
3.12
0.04
2.40
0.01
292
5
0.31
0.01
corn
3.11
0.02
2.41
0.01
309
6
0.29
0.02
castor
4.69
0.01
2.56
0.01
122
2
0.42
0.01
various seeds
3.10
0.02
2.43
0.01
371
5
0.27
0.01
soybean
3.09
0.01
2.41
0.02
390
7
0.30
0.02
castor
var
i
ous
seed
soybean
co
r
n
sunflower
p
e
anu
t
oliv
e
(ac
.
4.0%)
o
live
(
ac.
1
.6%)
olive (ac.
1.2%)
oliv
e
(ac
.
0.3%)
100
120
220
240
260
280
300
320
340
360
380
400
420
f
r
(MHz)
Fig. 4.15
Summarized comparative results of the averaged values of
f
r
for the considered
oils. The corresponding expanded uncertainty bars (with a confidence level of 95%) are also
reported
On a side note, it is important to point out a few aspects related to the used probe.
Generally, a short probe provides several benefits: a lower attenuation of the elec-
tromagnetic signal is achieved, small volumes of liquid are required, and, finally,
a higher mechanical stability between inner and outer conductors can be ensured.
On the other hand, short probes do not provide enough electrical length for the
electromagnetic signal in the LUT at low frequencies: this may represent an issue
when determining the value of the static permittivity,
ε
s
. In this regard, the choice
of the optimal length of the probe should start from preliminary considerations of
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