ABSTRACT
Reference material — material, sufficiently homogeneous and stable with reference to specified properties, which has been established as fit for its intended use in measurement or in examination of nominal properties. Certified reference material — reference material, accompanied by documentation issued by an authoritative body and providing one or more specified property values with associated uncertainties and traceabilities, using valid procedures. Homogeneity — condition of having a uniform structure or composition with respect to one or more specified properties. RM is said to homogeneous with respect to a specified property if the property value, as determined by tests on samples of specified size, is found to lie within the specified uncertainty limits, the samples being taken either from different supply units (bottles, packages, etc.) — between-bottle homogeneity, or from a single supply unit — within-bottle homogeneity. Stability — ability of a reference material, when stored under specified conditions, to maintain a stated property value within specified limits for a specified period.
