The gas which is made up of two or more kinds of gas mixing table, and the main concentration is marked, can meet the use requirement, this kind of gas is called general mixed gas.

For gas analyzers, gases such as 10% hydrogen, 5% or 10% argon mixture and 5% or 10% methane mixture, and the remaining argon mixture are used as carrier gas for gas chromatograms; A mixture of 40% hydrogen and the rest nitrogen is used as fuel gas for the hydrogen flame Total hydrocarbon detector. In addition, a mixture containing 20 to 60 percent oxygen and the rest argon is used to produce ozone for the chemical fluorescence analyzer.

In the determination of radioactive substances, the mixture used consists of 0.95 per cent isobutane, or 1.3 per cent butane, or 1.5 per cent propane, or 5-10 per cent shethane, all backed by helium. Too many of these gases are formed by mixing more than one of the following: xenon, neon, and krypton. Halogen light source production with bromomethane, chloromethane, hydrogen bromide, iodomethane, chloroform and other gases mixed with argon gas.

Deep sea respiration consists of a mixture of oxygen 20% ~ 60% and nitrogen or helium the rest. Laser gas contains 4% ~ 16% CO2, 10% ~ 25% N2, and the rest helium. The protective gas of metal heat treatment can be hydrogen 0.5% ~ 10%, the rest is mixture of argon 10% ~ 40%, 20% ~ 60%, and the rest is mixture of nitrogen and helium. Mixtures of photochemical reactions, animal and plant laboratories, and metal corrosion are hazardous, so nitrogen dioxide, sulfur dioxide, and hydrogen sulfide, etc. should be kept at low concentrations.