Bulk oxide determinations from a pair of portland cements provides the basis for calculation precision and accuracy values for X-ray fluorescence (XRF) analysis for both the fused glass bead and the pressed powder sample preparation. Approximately 45 laboratories provided six replicates analyzed in duplicate for two separate portland cements covering eleven analytes, CaO, SiO2, Al2O3, Fe2O3, SO3, MgO, Na2O, K2O, TiO2, P2O5, and Cl, with the laboratories roughly split between the two different sample preparations. Chemical data using traditional chemical analyses (the Reference Methods) from the Cement and Concrete Reference Laboratory (CCRL) proficiency test program were included for comparison to the XRF results. Precision measures for within- and between-laboratory performance are presented as 1-σ and 95 % limits (ASTM d2s). Accuracy criteria are based upon a two-sided 95 % prediction interval for the mean of two test results, defining the range of values one might expect for each analyte relative to a certified value of a reference material.
Citation: Technical Note (NIST TN) - 1816
NIST Pub Series: Technical Note (NIST TN)
Pub Type: NIST PubsReport Number:
accuracy, hydraulic cement, precision, qualification, X-ray fluorescence