ASTM D7317 Standard Test Method for Coagulated Pentane Insolubles in Used Lubricating Oils by Paper Filtration (LMOA Method)
11. Report
11.1 Report the percentage ofcoagulated pentane insolubles to two significant figures.
12. Precision and Bias
12.1 Precision - The precision of this test method was determined from the statistical analysis of an interlaboratory study (ILS), comprising six used railroad diesel engine oils measured four times each in 12 laboratories.
12.1.1 Repeatability - The difference between successive test results, obtained by the same operator with the same apparatus under constant operating conditions on identical test material would, in the long run, and in the normal and correct operation of the test method, exceed the following values only in one case in twenty:
0.061*(x + 1.77)
where:
x = average of the two results.
12.1.2 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, and in the normal and correct operation ofthe test method, exceed the following values only in one case in twenty:
0.237*(x + 1.77)
where:
x = average of the two results.
NOTE 1 - Precision is finite at a determined value of zero. Since the result of this test method is the difference of two weight determinations, it is possible to obtain negative numbers for a blank sample (true zero result) due to random weighing errors.
12.1.3 Calculated repeatability and reproducibility at selected insolubles values are given in Table 1.
12.2 Bias - The procedure in this test method has no bias because the mass percent of insoluble materials can only be defined in terms of this test method.
12.3 Relative Bias - Agreement between the results of this test method and those from Test Method D893 has not been investigated. In general, the two test methods are not expected to correlate.
13. Keywords
13.1 diesel; filtration; insolubles; LMOA; lubricating oil; pentane insolubles; used
