16. Report
16.1 Report the neutralization value as the arithmetic average of the three determinations of soluble activity.
16.2 Report the sludge as a percentage of the initial weight of the oil.
17. Precision and Bias
17.1 Use the following criteria for judging precision of test results on new, used, and reclaimed oils at the 95 % probability level.
NOTE 4 - The precision statements for this test method were based on two test specimens of each new, used, and reclaimed oils. Six laboratories participated. No research report is available.
17.1.1 Repeatability - The difference between 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.
where X is the average of two determinations on the same test sample.
17.1.2 Reproducibility - The difference between two single and independent results obtained by different operators working in different laboratories on identical test material would, in the long run, exceed the following values only one case in twenty.
where X is the average of the results submitted by each of two laboratories on the average of two determinations on the same test sample.
17.1.3 Note that the neutralization value for a single test specimen is itself the average of three concurrent titrations on a single oxidized test specimen. Do not consider this average suspect unless the range of the three titrations (largest value minus smallest value) exceeds 0.08 mgKOH/g.
17.2 Bias - No justifiable statement can be made on the bias of the procedure in this test method, since there is no accepted material suitable for reference in determining oxidation stability.
18. Keywords
18.1 acid; aging; electrical oil; insulating mineral oil; oxidation; sludge; stability; transformer