ASTM D1159 Standard Test Method for Bromine Numbers of Petroleum Distillates and Commercial Aliphatic Olefins by Electrometric Titration
11. Precision and Bias
11.1 Precision - The precision of this test method as determined by the statistical examination of interlaboratory test results is as follows:
11.1.1 Repeatability - The difference between successive 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 following values only in one case in twenty.
Petroleum distillates:
where: X = sample mean.
Commercial olefins: r = 3
11.1.2 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, exceed the following values only in one case in twenty:
Petroleum Distillates:
where: X = sample mean.
Commercial olefins: R = 12
11.2 Bias - The procedure for measuring bromine number has no bias because the value of bromine number can be defined only in terms of a test method.
NOTE 4 - The precision of this test method was determined using 1,1,1-trichloroethane as the sample dilution solvent and as a a component of the titration solvent. It is not known whether the precision estimates are applicable when using dichloromethane in place of 1,1,1-trichloroethane.
12. Keywords
12.1 aliphatic olefins; bromine number; electrometric titration; petroleum distillates