Intra- and Interlaboratory Approach for Certification of Reference Materials for Assuring Quality of Low-Alloy Steel Measurement Results

Abstract

Certified reference materials are versatile tools to support quality, correctness and credibility of measurement results. They are used to provide the traceability of the measurement results to the SI unit. In the present work, seven low-alloy steel reference materials were developed by the National Institute of Standards, Egypt. Homogeneity of the developed reference materials (RMs) was studied by X-ray fluorescence spectrometer (XRF) and atomic emission spectrometer, and the results proved that the produced RMs were homogeneous enough for establishing traceability of measurement results and internal and external quality control schemes. Characterization of reference materials composition was performed by four independent analytical methods: gravimetry, XRF, optical emission and atomic absorption spectrometry in different laboratories. The assigned values of the mass fractions of the various elements of the alloys and their associated uncertainty were calculated by the weighted mean approach.