ASTM D5187 Standard Test Method for Determination of Crystallite Size (Lc) of Calcined Petroleum Coke by X-Ray Diffraction
12. Report
12.1 Report the mean crystallite thickness to the first decimal as Lc = xx.x angstroms (Å).
13. Precision and Bias
13.1 The precision of this test method as determined by the statistical examination of inter-laboratory test results in which one operator in ten laboratories made duplicate analysis on each of six materials is as follows:
13.1.1 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 value only in one case in twenty:
Repeatability = 0.021X
where:
X = the average of two results in angstroms.
13.1.2 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 = 0.11X
where:
X = the average of two results in angstroms.
13.2 Bias - Since there is no accepted reference material suitable for determining the bias for the procedure in this test method for measuring crystallinity of petroleum coke, bias has not been determined.
14. Keywords
14.1 crystallinity; Lc; petroleum coke; X-ray diffraction
