ASTM D3240 Test Method for Undissolved Water In Aviation Turbine Fuels
10. Report
10.1 Report the result to the nearest whole number as ppm by volume of undissolved water in fuel, and also the sample volume used in the test. Report the temperature of the sample if available.

11. Precision and Bias
11.1 The precision (Note 3, Note 4) of this test method as determined by statistical examination of test results obtained by operator-instrument pairs at a common test site is as given in this section. Each operator used a separate instrument.
11.1.1 Repeatability - The difference between successive results obtained by the same operator with the same apparatus under constant operating conditions on identical test material would, in the long run, in the normal and correct operation of the test method exceed the following values only in one case in twenty.
Repeatability = 0.32x
where x = average of two results in parts per million volume over the range from 1 through 60 ppm V (Note 5).

1.1.2 Reproducibility - The difference between two single and independent results obtained by different operators working at a common test site on identical test material would, in the long run, exceed the following values only in one case in twenty.
Reproducibility = 0.47x

NOTE 3 - The reproducibility values above were estimates from results obtained at the same location and on the same day by seven operator/instruments testing identical samples. In the case of this test method it is not possible to obtain meaningful results when fuels are shipped to different locations since water would separate during shipment.

NOTE 4 - The presence of fuel additives such as corrosion inhibitors, fuel system icing inhibitors, and antistatic materials may affect the calibration of the test.

NOTE 5 - Sample size was not found to be a significant factor in precision. Data were analyzed using a log transformation but the repeatability results are expressed in untransformed units.

11.1.3 Bias - Since there is no accepted reference material suitable for determining the bias for the procedure in Test Method D3240 for measuring the undissolved water in aviation turbine fuels, bias has not be determined.

12. Keywords
12.1 calibrating standard; fluorescence; fluorescing standard; free water; sodium fluorescein; undissolved water; uranine