Standard gases and mixed gases are widely used in basic science, air pollution, medical diagnosis, petrochemical industry, metallurgical geology, atomic energy, microelectronics, optoelectronics and many other fields.
The standard gas is for users to make quantitative standards. Since the standard gas is a standard substance, it is a standard for measurement of value, and has the functions of reproduction, traceability, arbitration, preservation and transfer 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 standard gas preparation. In 1985, China also regarded this standard as a national standard (GB5274-85). The standard clearly requires that the relative uncertainty of the components of the standard gas must be indicated on the preparation certificate when it leaves the factory. Because the uncertainty runs through every link of the gas preparation process, it is of great significance for the gas distribution personnel to correctly understand the true meaning of the uncertainty formula.
Standard gases (Standard gases) refer to gas industry terms, and standard gases belong to standard substances. Standard materials are highly uniform, stable and accurate measurement standards. They have the basic function of reproducing, preserving and transferring the value. They are used to calibrate measuring instruments and measurement processes in the fields of physics, chemistry, biology and engineering measurement. , Evaluate the accuracy of the measurement method and the detection ability of the testing laboratory, determine the characteristic value of the material or product, and conduct the value arbitration.
Gas mixture refers to a gas that contains two or more effective components, or a gas whose content exceeds a prescribed limit although it is an ineffective component.