1
know where the stone and the pieces of root belong when we come back to get
2
a tare weight for the nonspecimen soil.
3
Vegetation is cut into quarter-inch increments (REECo 73).
We found
4 _it turns out to be much quicker than to leave the grass long because then
5
we: don't end up with a sieve covered with grass.
6 “goes -threugh the sieve.
almost
all
The grass does grind and
There is a mandatory requirement to wear rubber
7
gloves “for
of
the processing
steps.
We use
a steel
brush
8
(REECO 74) to-dislodge soil from stones that are large enough to pick up.
9. We went to. a_steel brush because we can clean it effectively in a sonic
10
cleaner.
11
Cleanup.is a critical step in the whole procedure.
We transfer the soil into the cans (REECo 75) and clean them off as
12.
they leave the pseudo glove box (REECo 76).
They are dried 24 hours at
13.
105°C (REECo 77).
14
in the processing.
15
took a wet weight of the entiré specimen as it came from the shipping bag.
16
We also weigh the bag itself, the-tape, the tag that's inside, the stones
17
and the roots to get a tare weight’for- the wet weight (REECo 78) from the
WhHethe drying is going on other activities take place
We go back . and we get into the data collection.
18 field specimen.
We
.
19
After the sample has been dried, we “get into the processing proper.
20
Grinding is-done by steel balls, rotating inside of a can that is turning
21
at
22
(REECo79) because that works the best or has withus.
23
note that all of the information that we have about-the specimen goes onto
between
130-140 rpm.
We
use
10
balls “for
24 the meta) can as well as into the record books.
25
a
2,000-gram
specimen
In passing I might
—~-- __
- The ball mill is.a series of rollers (REECo 80).
Each section, if you
26
wish, will grind 10 one-gallon cans.
They grind initially as shown on
27
Figure 29 for three hours.
28
for an hour, sieve again, regrind the remaining coarse material and sieve
We then sieve them, grind the coarse material
143