2, balloon inflation: because helium density is much smaller than air (air density of 1.29kg / cubic meter, helium density of 0.1786kg / cubic meter), and the chemical nature of the extremely inactive, safer than hydrogen (hydrogen can be burned in the air may cause an explosion), helium is commonly used in airships or advertising balloons in the filling of the gas.
3, inspection and analysis: instrumental analysis of commonly used nuclear magnetic **** vibration analyzer superconducting magnets need to use liquid helium cooling, gas chromatography analysis of helium is often used as a carrier gas, the use of helium permeability is good, non-combustible characteristics of helium, helium is also used in vacuum leak detection, such as helium mass spectrometry leak detector.
4, protective gas: the use of helium inactive chemical properties, helium is commonly used in magnesium, zirconium, aluminum, titanium and other metal welding protective gas.
5, other aspects: helium can be used as a high-vacuum devices, atomic nuclear reactors in rockets, spacecraft used to transport liquid hydrogen, liquid oxygen and other liquid propellants pressurized gas. Helium is also used as a cleaning agent for atomic reactors, in the field of marine development in the breathing gas mixture, gas thermometer filler gas and so on.