ASTM D7371 test method for biodiesel content in diesel fuel oil
ASTM D7371 Standard Test Method for Determination of Biodiesel (Fatty Acid Methyl Esters) Content in Diesel Fuel Oil Using Mid Infrared Spectroscopy (FTIR-ATR-PLS Method)
14. Report
14.1 Report the following information:
14.1.1 Volume % biodiesel by Test Method D7371, to the nearest 0.01 %.
15. Precision and Bias
15.1 Interlaboratory tests were carried out in 5 laboratories using 16 samples that covered the range from 1 to 20 volume %. The precision of the test method as obtained by statistical examination of interlaboratory results is summarized in Table 2 and Table 3.
15.2 Repeatability - For biodiesel concentrations between 1.00 and 20.00 volume %, the difference between successive test results obtained by the same operator with the same apparatus under constant operating conditions on identical test samples 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:
Repeatability = 0.01505(X + 14.905) volume %
where:
X = biodiesel concentration determined.
15.3 Reproducibility - For biodiesel concentrations between 1.00 and 20.00 volume %, the difference between two single and independent results obtained by different operators working in different laboratories on identical test samples 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:
Reproducibility = 0.04770(X + 14.905) volume %
where:
X = biodiesel concentration determined.
15.4 Bias - No information can be presented on the bias of the procedure employed in this test method because no primary reference material having an accepted reference value is currently available.
16. Keywords
16.1 biodiesel; biodiesel blend; biodiesel (FAME) content; FAME; fatty acid methyl esters; infrared spectroscopy
