ASTM D2162 Test Method for Basic Calibration of Master Viscometers and Viscosity Oil Standards
13. Precision and Bias
13.1 The precision of this test method as determined by statistical examination of interlaboratory test results is as follows:
13.2 Repeatability - The difference between two 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 this test method, exceed 0.1 % of their mean only in 1 case in 20.
13.3 Reproducibility - The difference between two single and independent test 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 this test method, exceed 0.35 % of their mean only in 1 case in 20.
13.4 Bias - Since this test method is designed to calibrate Master Viscometers and Viscosity Oil Standards to the primary standard (water), it has, by definition, no bias.
14. Keywords
14.1 kinematic viscosity; master viscometers; viscosity oil standards
