ASTM D1078 Test Method for Distillation Range of Volatile Organic Liquids
12. Report
12.1 Report the results in a manner conforming with the specifications of the material tested. If no definite manner of reporting is specified, report the corrected temperatures at each observed volume, and report the volume percentages of residue, recovery, and distillation loss.
13. Precision and Bias
13.1 Interlaboratory Study.
13.2 The precision of this test method was obtained from an interlaboratory study conducted in 2000 involving manual and automatic distillation procedures. The study involved six samples of different boiling point ranges, done in duplicate. Ten laboratories did automatic D1078 distillation, and five laboratories did manual D1078 distillation. It was found that the precision is dependent on the boiling point temperature. The data were statistically evaluated using the D2PP software available from ASTM.
13.3 Repeatability - Two results, each the mean of two runs, obtained by the same operator should be considered suspect if they differ by more than the repeatability values shown in Tables 4 and 5 at a 95 % confidence level.
13.4 Reproducibility - Two results, each the mean of two runs, obtained by operators in different laboratories should be considered suspect if they differ by more than the reproducibility values shown in Tables 4 and 5 at a 95 % confidence level.
13.5 Bias:
13.5.1 Absolute Bias - Since the temperature measuring devices specified by this test method are calibrated against the normal boiling point of toluene (99.9+ % purity), this test method has no bias with respect to pure toluene as a reference material.
13.5.2 Relative Bias Between Manual and Automatic D1078 Distillation - Statistical comparison between the variances of automatic and manual D1078 distillation results did not indicate any statistically significant difference. Statistical comparison of the averages of the six samples used in the study indicated that the paired-sample, two-tailed, t-test for the initial boiling point (IBP) and 50 % distillation point showed a small relative bias that is not statistically significant. A small but statistically significant bias was indicated for the automatic and manual D1078 dry point (DP). Table 6 gives a summary of the relative bias observed for the samples used in the study. The observed bias (if any) are only for the samples studied and may not be necessarily applicable to other samples.
NOTE 8 - In cases of dispute, the parties involved may agree to designate either the manual or the automatic method to be the referee test method. If an agreement on which method to designate cannot be made, the referee test method will be the manual method.
14. Keywords
14.1 distillation range; solvents
