GB 04269 - Edition 05 - July 12
9/10
A 200
About leak detection
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 is a 100 % green gas and has absolutely no environmental
impact on the atmosphere.
Helium was discovered by spectroscopy in a solar eclipse on August
18, 1868. The discovery in the sun’s chromosphere 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 gives 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 rectification. In contrary, Helium
is “mined” from natural gas and oil wells 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 5 ppm Helium in air.
Helium is a very light colorless element and it is one of the six noble
gases which means it doesn’t react with anything for all practical
intents and purposes. It’s the most difficult gas to liquefy.
It’s used as an inert shield gas to protect things from oxidation – and
of course as leak detection tracer gas.
Helium is commercialized in many different purity levels, the highest
level of purity is requested from some laboratories for fundamental
researches or very accurate analyses.
The use of the Helium as a tracer gas into a mass spectrometer
doesn’t require such attention. A purity in the range of 97 % to
99 % is enough.
There is absolutely no risk of accuracy lost or contamination for the
analyzer cell by using standard purity level of Helium gas.
About helium and
hydrogenated
nitrogen
Helium
Helium and leak detection:
which purity?
adixen Vacuum Products - ASM 380 Operating instructions
Summary of Contents for adixen ASM 380
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