ASTM D168 Standard Test Method for Coke Residue of Creosote
9. Report
9.1 Report the calculated amount of coke residue to the nearest 0.1 %.
10. Precision
10.1 Coke Residue, 0 to 2.5 % Range:
10.1.1 Repeatability - Duplicate values by the same operator should not be considered suspect unless they differ by more than 0.3 % absolute.
10.1.2 Reproducibility - The values reported by each of two laboratories should not be considered suspect unless they differ by more than 0.5 % absolute.
NOTE 2 - The estimated standard deviation of repeatability is 0.12 % absolute at 16 degrees of freedom (df). The estimated standard deviation of reproducibility is 0.18 % absolute at 14 df.
10.2 Coke Residue, 2.5 to 12 % Range:
10.2.1 Repeatability - Duplicate values by the same operator should not be considered suspect unless they differ by more than 12 % relative.
10.2.2 Reproducibility - The values reported by each of two laboratories should not be considered suspect unless they differ by more than 14 % relative.
NOTE 3 - The estimated standard deviation of repeatability is 4.1 % relative at 24 df. The estimated standard deviation of reproducibility is 4.9 % relative at 21 df.
11. Keywords
11.1 coke; creosote; residue
