Optical Emission Spectrometry (Spark OES), an important instrument for analyzing the composition of metal and alloy. Spark OES detected the percentage of elements in the ferrous and non-ferrous alloy, includes it's major metal matrix and other elements. The energy of spark burns the a thin surface of the metal sample, and generate the plasma. The excited atoms and ions in the plasma is detected by a spectrometer in the Spark OES instrument. Since each elements has it's characteristic peaks in certain wavelength(s) in the spectrum, one can analyze the composition of elements in the alloy, as well as their percentage. By the percentage of elements been detected, the grade of alloy is defined. Some Spark OES even designed PMT illuminate source for specific and increase its accuracy of specific elements. Such as GNR's S9 Atlantis Spark OES, the top level Spark OES.
Helium: ultra-low temperature cooling, vapor deposition, balloons of diving suits filling.
Neon: neon light or mercury lamp filling, plasma research, laser beam (He-Ne)
Argon: metal welding, OES spectrometer.
Some alloy are composed of nitrogen and it is needed to be analyzed. And nitrogen can react with metals in under high temperature, and result residues. (e.g. Magnesium Nitride.)
It is different. TIG welding uses argon as a shielding gas to oxidation on the welding point. Spark OES uses argon gas to isolate the elements in the atmosphere, which are also the composition of the alloy.
Since argon gas had been used as shielding gas on the discharge electrode, some Spark OES shares the argon to purge the optics chamber in the spectrometer. It will also consume the argon gas. However, some special designed Spark OES can largely reduce the consumption of argon gas to the minimum, such as GNR's Spark OES.
Not really. Too strong flushing will generate air entrainment result. The strength of GNR Spark OES had been optimized to the best air pressure while manufacturing.