Adixen ASM 142, Руководство пользователя

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About Helium and hydrogen
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Helium
Helium is the second most common element in the universe,
representing about 23 % of the total matter. 76 % is Hydrogen. All
other elements represent an insignificantly small fraction of the total.
Helium was discovered by spectroscopy in a solar eclipse on August
18, 1868. The discovery in the sun’s chronosphere gave the new
element its name: “helios” in Greek means “sun”. While Helium is
very common in the universe most of it is in the stars: on earth it
is actually not abundant. Since it is so light all the Helium present
during the formation of earth escaped to space. Helium is created,
deep in the earth from the radioactive decay of Uranium and Thorium
which also generates the earth its internal heat. On earth Helium was
discovered in 1881 by spectroscopy of Mount Vesuvio in Italy – the
volcanic gases emanated by the mountain showed the same lines in
the spectrum as already known from the sun.
Helium concentration in the atmosphere is 5 times bigger than the one
of Krypton and 60 times higher than Xenon. The heavier noble gases
are isolated from air by liquefaction and rectification process. Helium
as a contrary is “extracted” from natural gas and oil wells. Helium
comes up with the natural gas and is separated and stored. The
annual world wide production is ca. 3x10 7 m 3 or
4,500 tons.
Helium is constantly seeping up from the ground all around us, but it
is so light that almost all of it escapes into space fairly rapidly. On the
other hand there is a constant flow of Helium from space and the sun
to earth. This gives a dynamic equilibrium and is the reason for the
world wide constant concentration of ca. 5 ppm Helium in air.
Helium is a very light colorless element and it is one of the six noble
gases; it is the most difficult gas to liquefy.
Helium is a noble gas, which means it doesn’t react with anything for
all practical intents and purposes. It’s used as an inert shield gas to
protect things from oxidation – and of course as leak detection tracer
gas.
Helium is a 100 % green gas and has absolutely no environmental
impact on the atmosphere.
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