Spectrum WaterScout SMEC 300, Руководство по эксплуатации продукта, Страница: 19 / 24

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7. Weigh each of the filled containers.
8. For each container, take three
SMEC 300 readings. Take care
not to take readings too near the
edge of the container. It is rec-
ommended to take readings per-
pendicular to the sides of the con-
tainer. If using the handheld
reader, the reader should be in
Raw AD mode. If taking readings
with a WatchDog weather station
or mini-station, the channel the sensor is connected to
should be programmed to
Raw Sensor (raw) .
9. After taking the readings, completely air-dry the mate-
rial in each container. DO NOT MIX the material from
each container. Find the air-dry weight for the material in
each container.
10. The volumetric water content for each container is cal-
culated as follows:
Where:
VWC = Volumetric water content
M
wet-total
= Total mass of container and wet material
M
dry-only
= Mass of air-dry material
M
cont
= Mass of container
ρ
w
= Density of water (1g/ml)
V
cont
= Volume of container
11. You now have 18 VWC values (one for each con-
tainer) and 54 raw readings (three for each container). A
regression analysis can now be performed to relate raw
value to actual water content.
cont w
cont only dry total wet
V
M M M
VWC
*
) (
ρ
+ −
=
− −
Suggested sampling
locations
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