ASTM D4287 test method for high-shear viscosity using a cone/plate viscometer
10. Report
10.1 Report the following information:
10.1.1 Reference to this test method and the viscometer used,
10.1.2 Type and identification of the product under test,
10.1.3 Type of cone used,
10.1.4 Rate of shear at which the determination was made (in reciprocal seconds),
10.1.5 Temperature at which the determination was made,
10.1.6 Test results in poises, reported to the nearest 1 % of the total range, that is, 0.05 P for 0 to 5 P-cones, 0.1 P for 0 to 10 P-cones, etc.,
10.1.7 Any deviation, by agreement or otherwise, from the test procedures described, and
10.1.8 Date of the test.
11. Precision and Bias
11.1 Precision - On the basis of an interlaboratory test of this test method in which eight operators in four laboratories tested six paints ranging in viscosity from 0.8 to 7.9 P on analog cone/plate viscometers, the within-laboratory coefficient of variation was found to be 2.2 %, at 40 df. The between-laboratory coefficient of variation was found to be 6.9 % at 34 df. Based on these results, the following criteria should be used for judging the acceptability of results at the 95 % confidence level:
11.1.1 Repeatability - Two test results, each the mean of two determinations, obtained by the same operator should be considered suspect if they differ by more than 6.3 % relative.
11.1.2 Reproducibility - Two results, each the mean of two determinations, obtained by operators in different laboratories should be considered suspect if they differ by more than 19.9 % relative.
11.2 Bias - Since there is no accepted reference material suitable for determining the bias for the procedure in this test method, bias has not been determined.
12. Keywords
12.1 viscosity-paints/related coatings/materials; viscometer-ICI cone/plate; viscometer-cone/plate
