The result of a chemical measurement is consequence of a set of steps that begins with sample selection. The aim of this study was to evaluate the relative importance of the sampling in overall measurement uncertainty, taking as study case physicochemical measurements of diesel. The empirical method used was by duplicates, and the treatment of data sets was performed by four different statistical techniques: classic analysis of variance, robust analysis of variance and two different Range Statistics models. The choice must be backed by previous evaluation of data set in terms of normality, independence, presence of outliers and homogeneity of variance. It was found that Range Statistics produced most reliable results under different premises and for the variety of physicochemical parameters evaluated. Robust analysis of variance failed indicates proper influence of sampling even it is a test designed to work under the lack of some of the proper premises.

化学测量的结果是从样品选择开始的一系列步骤的结果。这项研究的目的是评估采样在总体测量不确定性中的相对重要性，以柴油的理化测量为研究案例。所使用的经验方法是重复进行的，数据集的处理是通过四种不同的统计技术进行的：方差的经典分析，方差的稳健分析和两个不同的范围统计模型。选择必须以先前对数据集的正常性，独立性，异常值的存在和方差的均一性为依据。结果发现，在不同的前提下以及对于所评估的各种理化参数，Range Statistics产生的结果最可靠。