15. Report
15.1 Report the results obtained in 13.13 as the DSEP rating by ASTM D7261 and identify whether a D Cell or DB Cell was used.
16. Precision and Bias D Cell and DB Cell
16.1 The precision of this test method is based on the interlaboratory studies #1451 conducted May 10-11, 2017 and #1387 conducted October 4-5, 2016. Each of eight participants tested samples in duplicate using his or her own instrument. Samples were tested blind: fuel containers were coded separately for each participant and testing orders were randomized by participant. Because of concerns for sample stability, all results were taken at a single site as discussed more fully in Practice D6300 3.1.13.3. As the precision was determined from results obtained at a single site, the reproducibility may not be comparable when results are obtained at different times from different sites. Precision was calculated in conformance with Practice D6300. Supporting data has been filed with ASTM International Headquarters and may be obtained by requesting Research Report: RR:D02-1876 and Research Report: RR:D02-1877.
16.1.1 Repeatability (r) - The difference between two independent results obtained by the same operator in a given laboratory applying the same test method with the same apparatus under constant operating conditions on identical test material within short intervals of time would exceed the following value with an approximate probability of 5 % (one case in 20 in the long run), in the normal and correct operation of the test method.
Repeatability
Where X is the average of the two results. See Tables 7 and 8.
16.1.2 Intermediate Precision - Between Operator/Apparatus Repeatability (r') - The difference between two single and independent results obtained by different operators applying the same test method at one laboratory using different apparatus on identical test material within short intervals of time would exceed the following value with an approximate probability of 5 % (one case in 20 in the long run), in the normal and correct operation of the test method.
Between Operator/Apparatus Repeatability
Where X is the average of the two results. See Tables 7 and 8.
16.1.3 Reproducibility (R) - Due to the instability of the sample fuel being tested, it is not possible to determine reproducibility in accordance with its definition in Practice D6300 and other ASTM documents.
16.2 Bias - At the time of the study, there was no accepted reference material suitable for determining the bias for this test method, therefore no statement on bias is being made.
17. Keywords
17.1 coalescence; diesel fuel; diesel fuel coalescer; DSEP rating; surfactant; water separation