ASTM D7214 Standard Test Method for Determination of the Oxidation of Used Lubricants by FT-IR Using Peak Area Increase Calculation
16. Report
16.1 Report the calculated PAI value in absorbance cm(-1) per mm: A.cm(-1)/mm.
16.2 It is recommended to report whether or not a dilution was required and ifso, the main reason for this dilution (that is, viscous sample, soot-containing oil, ester interference, etc.).
16.3 A report of the precise wavenumber of the points used for the base line for the measured area A is recommended.
17. Precision and Bias
17.1 Repeatability - The difference between successive results measured by the same operator with the same apparatus on identical test samples would, in the long run, in the normal and correct operation of the test method, exceed the following value in only one case in twenty:
For non-ester containing oils r = 6.8
For ester containing oils r = 0.10 (x + 17)
where:
x = the average of the two results.
17.2 Reproducibility - The difference between results measured by different operators working in different laboratories on identical test samples would, in the long run, in the normal and correct operation of the test method, exceed the following value in only one case in twenty:
For non-ester containing oils R = 16.9
For ester containing oils R = 0.61 (x + 17)
where:
x = the average of the two results.
17.2.1 A significant laboratory bias was observed for both ester and non-ester containing oils. This means that between laboratory bias is a major contributor towards this reproducibility.
17.3 Bias - The bias of this test method cannot be determined because there are no certified reference standards for these properties.
18. Keywords
18.1 differential spectrum; FT-IR; in-service lubricant; lubricant; oxidation measurement; PAI; used oil
16. Report
16.1 Report the calculated PAI value in absorbance cm(-1) per mm: A.cm(-1)/mm.
16.2 It is recommended to report whether or not a dilution was required and ifso, the main reason for this dilution (that is, viscous sample, soot-containing oil, ester interference, etc.).
16.3 A report of the precise wavenumber of the points used for the base line for the measured area A is recommended.
17. Precision and Bias
17.1 Repeatability - The difference between successive results measured by the same operator with the same apparatus on identical test samples would, in the long run, in the normal and correct operation of the test method, exceed the following value in only one case in twenty:
For non-ester containing oils r = 6.8
For ester containing oils r = 0.10 (x + 17)
where:
x = the average of the two results.
17.2 Reproducibility - The difference between results measured by different operators working in different laboratories on identical test samples would, in the long run, in the normal and correct operation of the test method, exceed the following value in only one case in twenty:
For non-ester containing oils R = 16.9
For ester containing oils R = 0.61 (x + 17)
where:
x = the average of the two results.
17.2.1 A significant laboratory bias was observed for both ester and non-ester containing oils. This means that between laboratory bias is a major contributor towards this reproducibility.
17.3 Bias - The bias of this test method cannot be determined because there are no certified reference standards for these properties.
18. Keywords
18.1 differential spectrum; FT-IR; in-service lubricant; lubricant; oxidation measurement; PAI; used oil