BS EN 15751 Automotive fuels - Fatty acid methyl ester (FAME) fuel and blends with diesel fuel - Determination of oxidation stability by accelerated oxidation method
11 Expression of results
Report the induction period, obtained from 10.1 or 10.2, in hours and rounded to the nearest 0.1 h.
If the induction period exceeds 48 h and the measurement is stopped, the result shall be reported as "> 48 h".
12 Precision
12.1 General
An interlaboratory test organized in 2007 at European level with the participation of 12 laboratories was carried out on 10 samples and gave the precision, derived from statistical analysis by EN ISO 4259. See Introduction for further work on paraffinic diesel fuel types.
Results from the calculation of precision estimates used shall be rounded to the nearest 0.1 h.
12.2 Repeatability, r
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 values calculated from the following formula in absolute value only in one case in twenty.
r = 0.22027 + 0.04344X
where
X is the mean of the two results.
12.3 Reproducibility, R
The difference between two single and independent test 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 values calculated from the following formula in absolute value only in one case in twenty.
R = 0.37269 + 0.19038X
where
X is the mean of the two results.
13 Test report
The test report shall specify:
a) a reference to this European Standard (i.e. EN 15751);
b) the type and complete identification of the product tested;
c) the sampling method used, if known (see Clause 7);
d) the temperature at which the determination was carried out;
e) the test result(s) obtained (see Clause 11), or if the repeatability has been checked, the final quoted result obtained;
f) all operating details not specified in this European Standard, or regarded as optional, together with details of any incidents which may have influenced the test result(s);
g) any deviation, by agreement or otherwise, from the procedure specified;
h) the date of test.
