OPTICAL EMISSION SPECTROSCOPY (OES) ANALYSIS
Material ID and Analysis of Most Alloys of Aluminum, Iron, Nickel, Cobalt, Copper and Titanium
Optical Emission Spectroscopy (OES) uses quantitative measurement of the optical emission from excited atoms to determine analyte concentration. A solid sample is atomized by an arc-spark discharge which provides sufficient energy to promote the electrons of atoms into high energy levels.
As the electrons decay back to their ground energy state light is emitted. The light travels through fiber optics where it is dispersed into its spectral components and is detected using photomultiplier tubes (PMT) and/or CCD arrays.
The intensity of the light, which is proportional to the concentration of the element in the sample, is recalculated internally from a stored set of calibration curves and is shown directly as percent concentration of the element.
All analyses are NIST traceable through the use of certified reference materials.
Reporting limits – Typically element concentrations are reported to 0.01 wt%, however in some cases trace elements can be analyzed to ppm levels.
Solid samples are prepared for analysis by machining or sanding a flat area, such that the sample fits over the hole in the stage.
Sample thickness requirement: typically 1/16 to 1/8 inches minimum depending on the base material and laboratory location.
Large hole stage: 15 mm in diameter
Small hole stage: 3 mm diameter (Note: small hole analysis is for iron-based materials only and requires carbon and sulfur analysis to be determined by combustion.)
Standard Test Methods
- ASTM E 415 – Low Alloy and Carbon Steels
- ASTM E 1251 – Aluminum Alloys
- ASTM A 751 – 400 Series Stainless Steels
- ASTM E 1086 – 300 Series Stainless Steels
- ASTM E 1999 - Cast Irons (PTL)
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