9. Calculation and Report
9.1 Add 3°C to the temperature recorded in 8.7 and report the result as the Pour Point, ASTM D 97. For black oil, and so forth, add 3°C to the temperature recorded in 8.7 and report the result as Upper Pour Point, ASTM D 97, or Lower Pour Point, ASTM D 97, as required.
10. Precision and Bias
10.1 Lubricating Oil and Distillate and Residual Fuel Oil.
10.1.1 Repeatability - The difference between successive test results, obtained by the same operator using 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 3°C only in one case in twenty. Differences greater than this should be considered suspect.
10.1.2 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 6°C only in one case in twenty. Differences greater than this should be considered suspect.
10.2 Bias - There being no criteria for measuring bias in these test-product combinations, no statement of bias can be made.
10.3 The precision statements were prepared with data on ten new (unused) mineral oil-based lubricants and sixteen assorted fuel oils tested by twelve cooperators. The mineral oil-based lubricants had pour points ranging from -48 to -6°C while the fuel oils had pour points ranging from -33 to +51°C. The following precision data were obtained:
