In order to reduce analysis cost and save samples, the homogeneity study of two titanium-certified reference materials was combined with the interlaboratory characterisation of that material. Samples were selected using a random-stratified sampling scheme and were sent to nine and 11 laboratories, respectively. The data were normalised to screen for trends in the production sequence, outliers and normality of the distribution of sample means. The non-normalised data were screened for outlying variances, and the uncertainty of homogeneity was evaluated using two-way analysis of variance. The uncertainty contributions determined were in all cases significant, but did usually not dominate the uncertainty of the assigned value. The findings were confirmed by a homogeneity study with a limited scope on one of the two materials. While the assessment of homogeneity using the approach was successful, the goal of reducing the consumption of samples and reducing analytical cost was only partially realised: a similar number of samples were consumed and 5 % – 10 % lower analytical cost than in a classical, separate homogeneity and characterisation study set-up was incurred.

中文翻译：

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评估同质性的替代设计：使用表征数据

为了降低分析成本和节省样品，将两种钛认证参考材料的同质性研究与该材料的实验室间表征相结合。使用随机分层抽样方案选择样本，并分别送到 9 个和 11 个实验室。对数据进行标准化以筛选生产顺序的趋势、异常值和样本均值分布的正态性。对非标准化数据进行异常方差筛选，并使用双向方差分析评估同质性的不确定性。确定的不确定性贡献在所有情况下都是显着的，但通常不会支配指定值的不确定性。对两种材料之一进行的同质性研究证实了这一发现。