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. This report is the second in a series on an Interlaboratory study on chemical analyses of hydraulic cements by X-ray fluorescence for the purpose of estimating precision and qualification criteria. Approximately 45 laboratories provided six replicates analyzed in duplicate for two separate portland cements containing ca. 5 % limestone, covering fifteen analytes, CaO, SiO2, Al2O3, Fe2O3, SO3, MgO, Na2O, K2O, TiO2, P2O5, Mn2O3, SrO, ZnO, Cr2O3, 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 1σ 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) - 1815
NIST Pub Series: Technical Note (NIST TN)
Pub Type: NIST Pubs