Dynamic Methods for Preparing Gas Mixtures

Metrological support of gas analytical measurements is carried out by transferring units of molar fraction and mass concentration of components from the State Primary Standard of units of molar fraction, mass fraction and mass concentration of components in gas and gas condensate environs. Reference materials (RMs) for the composition of gas mixtures in cylinders under pressure are used as transmission means, as well as gas mixture generators, the output of which is a gas mixture with known metrological characteristics. The main problem of this method is to ensure long-term stability of the mixture. The use of dynamic methods implemented in gas mixture generators, when the prepared gas mixture is used directly from the generator output, allows to significantly minimize or completely avoid this problem.In recent years, quite a lot of gas mixture generators manufactured by domestic and foreign manufacturers have appeared on the market. Therefore, a comparative analysis of various methods of dosing the initial components implemented in gas mixture generators and used for metrological support of gas analytical measurements seems relevant.The practical significance of the study lies in the analysis of the metrological, technical and operational characteristics of generators implementing various methods of dosing components of gas mixtures, which can be used by manufacturers of these measuring instruments to develop optimal technical solutions in the development and creation of new types of generators and dynamic installations designed to reproduce and transmit units of component content in gas environs.The presented review may be useful for teachers and students of specialized higher education institutions to enhance their knowledge in the field of metrological support for gas analytical measurements.

gas mixtures, static methods, dynamic methods, gas mixture generators, gas flow rate, mass concentration, mole fraction