Cooperative Calibration and Analysis of Cement Clinker Phases, Report 2

A cooperative calibration was carried out by ASTM Task Group C01.23.01 as part of an effort to assess the use of X-ray diffraction analysis for determining the proportion of tricalcium aluminate (cubic and orthorhombic), tetracalcium aluminoferrite, and magnesium oxide in portland cement and clinker. That calibration, including statistical analysis to determine precision and bias, was described in an earlier report. Since that previous rePOI4 some additional data have been submitted and the statistical analysis repeated. The subsequent analysis showed that the calibration precision were improved, though only slightly. With these additional data. Based on this statistical analysis, repeatability and reproducibility levels may be specified for analysis of these 4 phases in unknown mixtures prepared from the same materials. Replicate analyses in the same laboratory should differ by no more than 1.1 % (relative to the total clinker) [the previous level was also 1.1 %]. Replicate analyses in different laboratories should differ by no more than 1.7% (relative to the total clinker) [the previous level was 1.8%]. Overall, analyses should differ from the known value by no more than 1.7% (relative to the total clinker). The measured values differ from the known values by less than the reproducibility standard deviation, so there appears to be no bias in these results