68
⚫
Appendix
Dry the sample until still moist, ~15% water
content. Gentle warming can be used to
accelerate the process, but take care not to over-
dry in places, and allow time for the water content
to equilibrate throughout the sample before taking
a reading.
Reweigh.
W
m
= 1573g
Re-insert the WET150 into the moist sample and
again record the permittivity reading.
ε
0
= 9.06, I.e.
√
ε
0
= 3.01
Dry the sample thoroughly.
With clay soils this is usually achieved by keeping it
in the oven at 105°C for several hours or days (the
time required depends on the sample size and
porosity).
Weigh the dry sample in the beaker.
W
0
= 1400g
Calculate
w
The water content of the wet soil,
w
, can be
calculated from the weight of water lost during the
full drying process, (
W
w
–
W
0
) and its volume,
L
s
:
𝜃
𝑤
= (𝑊
𝑤
− 𝑊
0
) 𝐿
𝑠
⁄
= (1693 − 1400) 960
⁄
= 0.305
w
= 0.305
Calculate
m
The water content of the moist soil,
m
, can be
calculated from the weight of water lost, (
W
m
–
W
0
)
and its volume,
L
s
:
𝜃
𝑚
= (𝑊
𝑚
− 𝑊
0
) 𝐿
𝑠
⁄
= (1573 − 1400) 960
⁄
= 0.180
1573.0
1400.0
