... ,not combustion,or combustion under normal circutances,is an insert gas.2.Useless:It is for low-temperature superconducing technolgy and ... magnesium,zirconium,aluminium,titanium and other welding the protection of gas, GC also be used for the analysis of the carrier ... gas,the ballon inflated,with the protection of arc welding gas,mixed gas diving with the thermometer and ...