ASTM D4715 Test Method for Coking Value of Tar and Pitch (Alcan)
12. Report
12.1 Report the coking value to the nearest 0.1 mass %.
13. Precision and Bias
13.1 The following criteria shall be used for judging the acceptability of results (95 % probability).
13.1.1 Repeatability - Duplicate values by the same operator shall not be considered suspect unless the determined percentages differ by more than 1.2 % absolute.
13.1.2 Reproducibility - The values reported by each of two laboratories, representing the arithmetic average of duplicate determination, shall not be considered suspect unless the reported percentages differ by more than 2.3 % absolute.
13.2 Bias - Coking values by this test method are about 2 percentage points higher than those obtained by Test Method D2416.
14. Keywords
14.1 Alcan; coke-forming; coking value; fixed carbon; pitch; residue; tar
