ASTM D2427 Standard Test Method for Determination of C2 through C5 Hydrocarbons in Gasolines by Gas Chromatography
10. Precision and Bias
10.1 The precision of this test method as obtained by statistical examination of interlaboratory test results is as follows:
10.1.1 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, in the normal and correct operation of the test method, exceed the amounts shown for repeatability in Table 1 only in one case in 20.
10.1.2 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 amounts shown for reproducibility in Table 1 only in one case in 20.
10.1.3 If the concentrations of the individual hydrocarbons are summed so as to provide a result for total C5 and lighter olefins, and total C5 and lighter hydrocarbons, the following precision applies:
10.2 The precision was not obtained in accordance with RR:D02-1007, "Manual on Determining Precision Data for ASTM Methods on Petroleum Products and Lubricants".
10.3 Bias - Since there is no accepted reference method suitable for measuring bias for this test method no statement of bias can be made.
11. Keywords
11.1 C2 to C5 hydrocarbons; gas chromatography; gasoline