ASTM D4683 for measuring viscosity at high shear rate and high temperature
ASTM D4683 standard test method for measuring viscosity at high shear rate and high temperature by tapered bearing simulator
13. Report
13.1 Report the apparent viscosity to the nearest 0.01 cP (mPa•s) at 150°C and 1 x 10(6) s(-1) shear rate.
14. Precision and Bias
14.1 Precision - The following criteria should be used for judging the acceptability of results:
14.1.1 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, in the normal and correct operation of the test method, exceed the following values only in one case in twenty:
2.3 % of the mean
14.1.2 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:
3.6 % of the mean
14.1.3 Eight laboratories were used in a program to obtain the precision statement. Statistical analysis was obtained using ASTM engine oils in the range from 2.4 to 4.8 mPa-s. The test series included SAE 0W-30, 5W-20, 5W-30 (4) 10W-30, 10W-40 (2), 15W-40, 20W-50, and 30 grade oils.
14.2 Bias - Since there is no accepted reference material suitable for determining the bias for this test method, bias cannot be determined.
14.3 Relative Bias - Results from this test method were found, in an interlaboratory study, to agree with those from Test Methods D4741 and D5481. They can be expected to give, on average in the long run, the same results for the same oil.
15. Keywords
15.1 dynamic viscosity; high shear viscosity; high temperature viscosity; rotational viscometer
