ASTM D2981 Test Method for Wear Life of Solid Film Lubricants in Oscillating Motion
11. Report
11.1 The report shall include the following:
11.1.1 Report the friction force in both directions at 50, 100, and 1000 cycles. Record the number of revolutions to failure, (point after wear-in at which a coefficient of friction of 0.1 is reached).
11.1.2 Indicate where failure occurred, whether in the inside, middle or outside of the wear track of the test ring.
12. Precision and Bias
12.1 Precision - The following criteria should be used for judging the acceptability of test results (95 % probability).
12.1.1 Wear Life Measurement:
12.1.1.1 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, and in the normal and correct operation of the test method, exceed 25 % of the mean only in one case in twenty.
12.1.1.2 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, and in the normal and correct operation of the test method, exceed 33 % of the mean only in one case in twenty.
12.2 Bias - Since there is no accepted reference material suitable for determining the bias for the procedure in Test Method D2981 for measuring wear life, no statement on bias is being made.
13. Keywords
13.1 oscillating; solid film lubricant; wear friction
