ASTM D4815 Standard Test Method for Determination of MTBE, ETBE, TAME, DIPE, tertiary-Amyl Alcohol and C1 to C4 Alcohols in Gasoline by Gas Chromatography
15. Precision and Bias
15.1 Precision - The precision of this test method as determined by a statistical examination of interlaboratory test results is as follows:
15.1.1 Repeatability - The difference between successive results obtained by the same operator with the same apparatus under constant operating conditions on identical test materials would, in the long run, in the normal and the correct operation of the test method, exceed the following values in Table 4 only in one case in twenty.
where X is the mean mass % of the component.
15.1.2 Reproducibility - The difference between two single and independent results obtained by different operators working in different laboratories on identical material would, in the long run, exceed the following values in Table 4 only in one case in twenty.
where X is the mean mass % of the component.
15.2 Bias - The National Institutes of Standards and Technology (NIST) provides selected alcohols in reference fuels. As an example, the following standard reference materials (SRM) in reference fuels are available as described in the NIST Standard Reference Catalog.
16. Keywords
16.1 alcohols; DIPE (disopropylether); ETBE (ethyl tert-butylether); ethers; gas chromatography; gasoline; MTBE (methyl tert-butylether); oxygenates; TAME (tert-amylmethylether)