ASTM D1744 standard test method for determination of water in liquid petroleum products by Karl Fischer reagent
11. Calculation or Interpretation of Results
11.1 Calculate the water content of the sample as follows:
Water, mg/kg = (C F x 1000) / [W or A x G]
where:
C = millilitres of reagent required for titration of the sample,
F = water equivalence, milligrams mg water/mL,
1000 = factor for converting to parts per million,
W = grams of sample used = A x G,
A = millilitres of sample used, and
G = relative density of the sample.
12. Precision and Bias
12.1 The precision of this test is not known to have been obtained in accordance with currently accepted guidelines (for example, in Committee D02 research report RR:D02-1007, Manual on Determining Precision Data for ASTM Methods on Petroleum Products and Lubricants). These results apply only to aviation turbine fuel. Difficulties encountered in distributing stable samples have prevented development of additional data.
12.2 The precision of the method as obtained by statistical examination of interlaboratory test results is as follows:
12.2.1 Repeatability - The difference between successive test 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 one case in twenty:
12.2.2 Reproducibility - The reproducibility of the method has not been determined because of the difficulty encountered in maintaining sample integrity when distributing them to the cooperator's laboratories.
12.3 Bias - The bias of this test method has not been determined.
13. Keywords
13.1 Karl Fischer; petroleum products; water