42 
BULLETIN 1375, U. S. DEPARTMENT OF AGRICULTURE 
For correct results, it is essential that the same care which is used 
in obtaining the sample be observed in handling the sample after it 
is drawn from the grain or after it is weighed for the test. If ex- 
posed to the air, samples will lose moisture in accordance with the 
percentage of water in the sample and the condition of the atmos- 
phere. An experimental test with 100 grams of wheat containing 
14.5 per cent of moisture showed a loss of 0.20, 0.35, 1.10, and 1.90 
per cent when ex- 
posed to the air of 
the laboratory for 
periods of one-half, 
1, 4, and 26 hours, re- 
spectively. A second 
lot of wheat, contain- 
ing 16.1 per cent of 
moisture, lost mois- 
ture to the extent of 
0.50, 0.75, 1.75, and 
3.20 per cent, respec- 
tively, during the 
same periods under 
identical treatment. 
Figure 26 shows the 
type of metal can 
and moisture-proof 
sample bag used by 
the offices of Federal 
Grain Supervision 
for the purpose of 
obtaining samples for 
moisture tests and 
other grading factors. 
The sampling de- 
vices and the methods 
used for obtaining 
correct samples of 
grain are fully de- 
scribed in United 
States Department 
of Agriculture Hand- 
book, U. S. G. S. A. 
Form Xo. 90. 
Fig. 26. — Air-tight sample can and moisture-proof sample 
bag used by Offices of Federal Grain Supervision for 
handling samples of grain to be tested for moisture 
content. The sample" bag is not desirable for this 
purpose unless the moisture test can be made within 
an hour or two from time of sampling 
SPECIAL POINTS FOR CONSIDERATION 
(1) The moisture tester should be installed in a place where it 
will not be exposed to strong air current. 
(2) The standard tester is equipped for heating with illuminating 
gas. 
(3) The wire gauze with asbestos center should be kept in good 
condition, and so adjusted that the flame plays directly in the center 
of the asbestos. 
