Estimate The Initial Water Content - UMS Hyprop User Manual

Perform a measuring campaign

6.4 Estimate the initial water content

To get a somewhat realistic display of the pF/WC characteristic
during the campaign it is necessary to estimate the water content at
the beginning of a measurement.
After the campaign, the initial water content is determined precisely
by oven drying and weighing the sample and calculating the
volumetric value. This actual water content is then used for the
calculations.
To estimate the water content before a measurement weigh the
complete and saturated HYPROP assembly. The software will
withdraw the tare weight of sensor unit and sampling ring.
The difference is the sum of soil matter and water. The density of soil
and water as well as the volume are known values with which the
water content can approximately be calculated. The result is only
approximate as not all pores are filled with water and densities vary.
Assuming that all pores are water filled the porosity  is equal to the
saturated water content 
The software then will calculate the
s.
saturated water content as follows:
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