Methods and Devices for the Preparation of Standard Gas Mixtures

A review of methods for the preparation of standard gas mixtures (SGMs) with the known concentrations of organic and inorganic gases and vapors is presented. The classification of methods is proposed and their advantages and disadvantages are compared. Along with the widely known thermal diffusion and gasextraction methods and devices for the preparation of SGMs functioning on their basis, i.e., sources of gas and vapor microflows and vapor-phase sources of gas mixtures, the review considers and discusses metrological possibilities proposed by Russian researchers of chromatomembrane and chromato-desorption methods of SGM preparation and corresponding instrumentation.