ASTM D2415 Standard Test Method for Ash in Coal Tar and Pitch
11. Report
11.1 Report the weight percent of ash to the nearest 0.01 %.
12. Precision and Bias
12.1 The following criteria shall be used for judging the acceptability of results (95 % probability):
12.1.1 Repeatability - Duplicate values by the same operator shall not be considered suspect unless the determined percentages differ by more than 0.01.
12.1.2 Reproducibility - The values reported by each of two laboratories, representing the arithmetic average of duplicate determinations, shall not be considered suspect unless the reported percentages differ by more than 0.03.
12.2 Bias - This procedure has no bias because the value of ash is defined in terms of this test method.
13. Keywords
13.1 ash; inorganic matter; pitch; tar
