Standard Reference Material

any one of the substances (materials) with precisely known and officially certified values of variables peculiar to a given substance. Standard reference materials quantitatively characterize the content of isotopes, elements, and compounds. An example is seen in the standard reference material for stainless steel, which is certified by chemical composition. These materials also quantitatively characterize the properties of a given substance, as in the standard reference material for benzoic acid, which is certified by the specific heat of combustion, and certain technical variables, as in the standard reference material for the thickness of the epitaxial structures of silicon. Owing to their purpose, standard reference materials belong to the class of metrological means known as measures. They are prepared through special technological processes, and the values of the certified quantities are established in accordance with the results of a predetermined program of study of standard reference materials of each type.

Standard reference materials are widely used to control the accuracy of the results of quantitative determinations of the characteristics of substances and to calibrate instruments for making these determinations. The materials are used primarily in the prospecting, mining, and treating of ores, the production and consumption of metals, alloys, fuels, and lubricants, and the control of raw materials and other materials supplied through agreements on international economic cooperation. They are also important in public health (clinical chemical analyses) and in the monitoring of environmental pollution. Because of the great importance of standard reference materials, the production and application of the materials have attracted the attention of metro-logical organs in a number of countries and have figured in activities of a number of international organizations. The French term for these materials is materiaux de référence, and the German term, Normalproben.