ASTM D972 Test Method forEvaporation Loss of Lubricating Greases and Oils
11. Calculation
11.1 Calculate the evaporation loss of the sample as follows:
Evaporation loss, mass % = [(S - W)/S] x 100
where:
S = initial mass of sample, g, and
W = mass of sample, g, after the test.
12. Precision and Bias
12.1 The precision of this test method is not known to have been obtained in accordance with currently accepted guidelines (in Committee D-2 research report RR: D02-1007, "Manual on Determining Precision Data for ASTM Methods on Petroleum Products and Lubricants").
12.2 The precision of this test method as determined by statistical examination of interlaboratory results is as follows:
12.2.1 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 the test method, exceed the following value only in one case in twenty:
0.025M
where:
M = mean of two values
12.2.2 Reproducibility - The difference between two single and independent 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 the test method, exceed the following value only in one case in twenty:
0.10M
where:
M = mean of two values
12.3 Bias - The procedure in this test method for measuring evaporation loss of lubricating greases and oils has no bias because the value of loss in mass is defined only in terms of this test method.
13. Keywords
13.1 evaporation; grease; oil; oil bath; rotameter; volatiles
