ASTM D5004 Standard Test Method for Real Density of Calcined Petroleum Coke by Xylene Displacement
14. Report
14.1 Report to the third decimal place the average of duplicate determinations that agree within 0.007 g/cm3. When this agreement is not met, the values are considered suspect and another duplicate set shall be run. Report the average of all results agreeing within 0.007 g/cm3. If the second set also fails to agree within 0.007 g/cm3, report the average of all four values. The operator shall also report if the second set of duplicate determinations fail to agree within 0.007 g/cm3.
15. Precision and Bias
15.1 The precision of this test method as determined by the statistical examination of interlaboratory test results is as follows:
15.1.1 Repeatability - The difference between successive results by the same operator using the same apparatus under constant operating conditions on identical test materials, will in the long run, in normal and correct operation of the test method, exceed the following values only in one case in twenty: repeatability = 0.0067.
15.1.2 Reproducibility - The difference between two single and independent results obtained by different operators working in different laboratories on identical test materials, will in the long run, in normal and correct operation of the test method, exceed the following values only in one case in twenty: reproducibility = 0.0156.
15.2 Bias - Since there is no accepted reference material suitable for determining the bias for the procedure in this test method for measuring the real density of calcined petroleum coke, no statement on bias is being made.
16. Keywords
16.1 calcined petroleum coke; petroleum coke; pycnometer; real density; xylene displacement
