ASTM D6616 Standard Test Method for Measuring Viscosity at High Shear Rate by Tapered Bearing Simulator Viscometer at 100°C
16. Report
16.1 Report the apparent viscosity to the nearest 0.01 mPa·s (cP) at 100°C and 1·10(6)s(-1) for each test oil for either the manual or automated protocols.
17. Precision and Bias
17.1 Precision - The following criteria should be used for judging the acceptability of results from either the manual protocol or the automated protocol:
17.1.1 Repeatability - The difference between two 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 in one case in twenty.
1.2 % of the mean.
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, in the normal and correct operation of the test method, exceed the following values only in one case in twenty.
3.5 % of the mean.
17.1.3 Ten laboratories submitted data used in the round robin program to obtain the precision statement. Statistical analysis was obtained on ASTM engine oils covering an approximate range of viscosities from 5 to 12 mPa·s (cP) at 100°C. The test series of engine oil was composed of the following engine oils: SAE 0W-10 (1), 5W-30 (1), 15W-40 (1), 20W-40 (2), 20W-50 (1), 25W-30 (1), 30 (1), and 40 (1) for a total of nine engine oils, These nine oils covered a viscosity range of approximately 5 cP mPa·s to 12 cP mPa·s at 100°C.
17.2 Bias - There is no accepted reference material suitable for determining the bias of this test method.
17.3 Relative Bias - Results from this test method were found, by an interlaboratory test study, to agree with those from Test Method D4741 at 100°C.
18. Keywords
18.1 dynamic viscosity; high shear rate viscosity; high shear rate viscosity at 100°C; high shear viscosity; high temperature viscosity; rotational viscometer; Tapered Bearing Simulator Viscometer
