Appendix C—Creating a customized calibration equation
Page 70
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4.
Prepare a table to record the SF readings per depth plane. Do not
average your readings. Record them separately.
5.
Dig a trench beside the access tubes (approx. 30 cm).
6.
Use three thin walled stainless steel rings to sample soil water and bulk
density.
Notes:
•
Make sure that the area ratio of the cylinder is less than 0.1, i.e. the
area of the cross section of metal to that of soil.
•
For a 75 x 75 mm cylinder, 16 gauge tubing gives maximum wall
thickness.
•
The area ratio for these samplers is 0.09.
7.
Drive the rings in so that they just touch the access tube.
8.
Stop driving when the centre of the ring matches the centre of the
sphere of influence of the sensor field.
9.
Use a series of platforms to sample at each depth.
Notes:
•
Each sample point has sampling rings driven in by a sledge-
hammer via a sampling ring tube extension.
•
Remove the soil above the sampling depth without compressing the
layer to be volume sampled.
10.
Remove soil samples with sufficient over burden (excess soil) and trim
each core with care using a spatula
Note:
Record any loss of soil from the sample ring.
11.
Store samples in sealed plastic bags.
12.
Conduct the gravimetric soil moisture content and bulk density
determination using the standard technique as soon as possible.
Note
: The bulk density is defined as the ratio of the mass of a given
sample to its bulk volume. The mass is obtained by drying the sample
at 105
o
C to constant weight, and the volume is the volume of the core
sampler.
13.
Calculate as follows:
If:
•
Mw = wet mass of soil core (g)
Summary of Contents for Diviner 2000
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