Optical emission spectrometry OES permits a very accurate analysis of metallic materials with a high detection limit, whereby the characteristic is used that each element or its ions emits a specific light spectrum with the corresponding amplification.
This necessitates the atoms initially being converted to an ionized state. In the event of spark excitation and via pulsed spark discharges, a small quantity of metal is initially melted, evaporated, atomized, and finally ionized at the surface.
The light emitted by the sample travels through a diffraction grid and complex optics to a CCD line where it is analyzed and evaluated. Quantification is on the basis of calibration lines. This means that calibration must be in place for the materials to be examined.
In the analysis of metallic materials, spark OES is superior to other, often significantly more expensive methods in several respects. Thanks to the relatively large focal spot (diameter 5–8 mm), this method is very integral and resistant to structural inhomogeneities, such as deposits. The detection limit is much lower than for EDX, for example. Important elements such as carbon and nitrogen in steel can therefore be determined more accurately. Furthermore, sample preparation is conceivably simple by means of sample overlapping.
We not only measure the material composition for you. You always benefit from the expertise of experienced metallographers and material scientists. And your particular problem can make it necessary to carry out more detailed tests, such as REM/EDX, TOF-SIMS , XPS , FT-IR, or ICP-MS. We offer all of these Methods as a package from a single source.
The very extensive material database comprising international standards permits a measured composition to be allocated exactly to a certain material.
Mechanical and plant engineering
SGS INSTITUT FRESENIUS GmbH
Königsbrücker Landstr. 161
t +49 351 8841-200