Analytical Accuracy of Standard Gases

 Standard gases and mixed gases are widely used in basic science, air pollution, medical diagnosis, petrochemical, metallurgical geology, atomic energy, microelectronics, optoelectronics and many other fields.

      The standard gas is for users to make quantitative standards. Because the standard gas belongs to the standard substance, it is the standard for measuring the value. It has the functions of reproduction, traceability, arbitration, preservation and transmission of the value. Therefore, the accuracy of gas distribution is of great significance in standard gas production, otherwise users cannot use it for quality analysis and control. As early as 1981, the International Organization for Standardization (ISO) formulated an international standard for the preparation of standard gases, and in 1985, my country also regarded this standard as a national standard (GB5274-85). The standard clearly requires that the relative uncertainty of the composition of the standard gas must be indicated on the preparation certificate when it leaves the factory. Since the uncertainty runs through every link of the gas preparation process, it is of great significance for the gas dispenser to correctly understand the true meaning of the uncertainty formula.

      Standard gases refer to gas industry terms, and standard gases belong to standard substances. Reference materials are highly homogeneous, well-stabilized and quantitatively accurate determination standards. They have the basic function of reproducing, preserving and transmitting quantitative values. They are used in the fields of physical, chemical, biological and engineering measurement to calibrate measuring instruments and measuring processes. , evaluate the accuracy of the measurement method and the testing ability of the testing laboratory, determine the characteristic value of the material or product, and conduct quantitative arbitration, etc.

      Mixed gas (gas mixture) refers to the gas containing two or more effective components, or although it is a non-effective component but its content exceeds the specified limit.