ASTM D5763 Standard Test Method for Oxidation and Thermal Stability Characteristics of Gear Oils Using Universal Glassware
12. Report
12.1 Report the amount of filterable sludge on the filter to the nearest 0.01 g.
12.2 Report the amount of adherent sludge on the oxidation tubes to the nearest 0.01 g.
12.3 Report the total amount of sludge to the nearest 0.01 g or to the nearest 0.01 %.
12.4 Report the viscosity increase in percent.
12.5 Report oil loss to the nearest 0.01 g or percent.
13. Precision and Bias
13.1 Precision - The precision of this test method as determined by the statistical examination of the inter-laboratory test results is as follows.
13.1.1 Total Sludge:
13.1.1.1 Repeatability - The difference between successive results obtained by the same operator with the same apparatus under constant operating conditions on identical test materials 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:
Repeatability = 0.42√x = g(%)
where:
x = found mean value
13.1.1.2 Reproducibility - The difference between two single and independent operators working in different laboratories on identical material would in the long run, exceed the following values only in one case in twenty:
Reproducibility = 1.4√x g/100 g(%)
where:
x = found mean value.
13.1.2 Viscosity Increase:
13.1.2.1 Repeatability - The difference between successive results obtained by the same operator with the same apparatus under constant operating conditions on identical test materials would in the long run, in the normal and correct operation of the test method, exceed the following values only in one in twenty:
Repeatability = 0.058 (x)2 = %
where:
x = found mean value.
13.1.2.2 Reproducibility - The difference between two single and independent results obtained by different operators in different laboratories on identical material would, in the long run, exceed the following values only in one case in twenty:
Reproducibility = 0.14 (x)2 = %
where:
x = found mean value.
13.1.3 The precision for filterable sludge, adherent sludge, and oil loss were not determined.
13.2 Bias - There is no accepted reference material suitable for determining the bias for this test method; therefore, bias has not been determined.
13.2.1 The round-robin test used to determine the precision and bias consisted of eleven laboratories, five gear oil samples, and duplicate testing per sample per laboratory.
14. Keywords
14.1 extreme pressure gear oils; gear oil; lubricants; non-extreme pressure gear oils; oxidation; sludge; universal oxidation/thermal stability test glassware; universal oxidation test; viscosity increase
