12. Calculation
12.1 Calculate the filterable insolubles mass (A) in milligrams per 100 mL. Subtract the mass of the blank (bottom) filter W1, in milligrams, from that of the sample (top) filter W2, in milligrams, (11.4) and divide by 3.5 to reduce the result to a 100-mL basis.
12.2 Calculate the adherent insolubles mass (B) in milligrams per 100 mL. Subtract the tare mass of the blank (W3) and sample (W4) beakers from their final masses (W5), (W6) respectively. Subtract the mass of the blank from the corrected mass of the adherent insolubles (11.5) and divide by 3.5.
where:
W3 = tare mass of the blank beaker, mg,
W4 = tare mass of the sample beaker, mg,
W5 = final mass of the blank beaker, mg, and
W6 = final mass of the sample beaker, mg.
12.3 Calculate the total insolubles mass (C) in milligrams per 100 mL as the sum of the filterable insolubles (A) and the adherent insolubles (B).
C = A + B
where:
C = total insolubles, mg/100 mL,
A = filterable insolubles, mg/100 mL, and
B = adherent insolubles, mg/100 mL.
NOTE 5 - Some specifications may require results in SI units of g/m3 rather than as mg/100 mL. In such cases, the values in mg/100 mL can be converted to SI units by multiplying by ten.
13. Report
13.1 Report total insolubles (C) in mg/100 mL, to the nearest 0.1 mg/100 mL
13.2 A report of filterable insolubles (A), and the adherent insolubles (B) is optional. Report units in milligrams per 100 mL.
14. Precision and Bias
14.1 Precision - The precision (see Table 1) of this test method as determined by statistical examination of interlaboratory results is as follows:
14.1.1 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 values only in one case in twenty:
14.1.2 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, in the normal and correct operation of the test method, exceed the following values only in one case in twenty:
14.2 Bias - Since there is no accepted reference material suitable for determining the bias for this test method no statement on bias is being made.
15. Keywords
15.1 diesel fuel; filterable insolubles; middle distillate fuel; oxidation stability