ASTM D3829 Predicting the Borderline Pumping Temperature of Engine Oil
12. Report
12.1 Report the predicted BPT as determined in 11.1 - 11.3.
12.2 Alternatively, it may be desirable to report that the BPT is below a certain specified temperature.
12.3 Alternatively, report apparent viscosity and yield stress at the measurement temperature.
13. Precision and Bias4
13.1 The precision of this test method as obtained by statistical examination of interlaboratory test results of 13 oils whose BPT varied from -14.5 °C to -36 °C is as follows:
13.2 Repeatability - The difference between successive test results obtained by the same operator with the apparatus under constant operating conditions on identical test materials, would in the long run, in the normal and correct operation of this test method exceed 1.3 °C only in one case in twenty.
13.3 Reproducibility - The difference between two single and independent test results, obtained by different operations working in different laboratories on identical test material, would in the long run, in the normal and correct operation of this test method, exceed 3.2 °C only in one case in twenty.
13.4 Bias - No justifiable statement can be made on the bias of the procedure described above, since all determinations are relative to the calibration fluid.
14. Keywords
14.1 borderline pumping temperature; viscosity; yield stress
