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At least two readings
accuracy, two readings ate usually sufficient if they differ by not more than
For work of ordinary
up to 40, one unit for readings between 40 and 50 and half a unit from 50
two units for readings
to 55. Between 55 and
should agree within about
Correcting for sample temperature
Ille temperature con•ections included in the calibration data scales or sheets are only
valid if the sample and cell are at the same temperature. Although this will normally be so,
temperature differences can occur in situations such as testing grain that is still hot after passing
through a drying process. Unless the time can be spared to let the grain cool down the reading
will not be correct. If the normal scale temperature correction is made for the temperature of the
sample, the possible measurement inaccuracy is as shown below; this includes the basic
inaccuracy of ±0.5%.
If this degree of error is not acceptable it may be possible to save time by gently heating
up the test cell to match the temperature of the grain.
Temperature difference between
cell and sample,
This shows that if the total error must be within say, 2%, the maximum permissible
temperature difference is 14 0 C (25 0 F).
46882-171 D
Apr. 92
should be taken. If these differ, one or two more should be taken.
60 the equivalent moisture content scale contracts rapidly and readings
0.1 unit.
soc
100C
150C
200C
OPERATION
Total inaccuracy
moisture mntent
1.0%
1.6%
2.1%
2.7%
13
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