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The following table gives general guidance for the selection of sample size for various expected
moisture levels. Note that the maximum sample size is also limited by the sample bottle. Do not
fill the bottle over half full.
Table 1 - Sample Size
Expected Moisture
Use
.001 - .015% or 50-150 ppm
1.5 - 2 grams
.015 - .035% or 150-350 ppm
0.5 - 1.5 grams
.035 - .075% or 350-750 ppm
1 - 2 grams
.075 - .150%
0.5 - 1 gram
.150 - .350%
0.2 - 0.5 gram
.350 - .750%
0.1 - 0.2 gram
.750 - 1.5%
0.05 - 0.1 gram
These are only guidelines. Experiment with your sample to refine the size estimates to achieve
your desired speed and accuracy. Note that if you are using a rate-ending criterion, and the peak
moisture rate is less than five (5) times the rate threshold, the sample sizes should not be allowed
to vary more than about 10%. Larger variation of sample size will lead to a larger variation of
results. For your particular application, call AZI Customer Service at (800) 528-7411 or
(602) 470-1414 for assistance in developing specific parameters.
After determining the optimum test parameters, repeat the test once to confirm the results.
For performance data, run 3 to 5 tests and use the following steps to determine the statistics.
•
If this instrument is not 21 CFR, Part 11 compliant, select
STORED DATA
from the
MAIN MENU
,
•
Select ANALYZE STORED DATA,
•
Select the test results you want to analyze, and
•
Press
[Calc]
.
If this is a 21 CFR, Part 11 compliant instrument, all readings must be recorded by hand; AZI
recommends using a printer to capture the values. The calculations must be performed on a
calculator since the instrument’s storage and analysis functions are disabled.
Mean, Standard Deviation, and Coefficient of Variation are calculated using the following
formulas.
•
Mean = total of results divided by number of results.
•
Standard Deviation =
1
-
n
x
-
x
2
)
(
Σ
•
Coefficient of Variation = Standard Deviation divided by Mean times 100%
