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Optical emission spectroscopy


Introduction to OES

Spark-Optical Emission Spectrometry (OES) is an analytical technique used to obtain elemental information from solid metals. It is employed in many industries and applications where solid metal materials have to be analyzed on their chemical composition. As long as the material is electrical conductive, OES can be applied.

What is OES and how does it work?

The basic concept of all spectrometers is a radiation source, a sample and a detection system. In (spark)-OES a spark is generated between the sample and a counter-electrode,the excited atoms emit light of specific wavelengths. The wave-length of the light being emitted is characteristic for each element, the intensity indicates the concentration of the element. Within the spectrometer, a grating is used to split the light into various wavelengths, detectors - mounted in a circle-set-up, detect the light for the various elements.

Spectrometer systems are generally divided into two main groups: classic systems using dedicated photo-multipliers (PMT) for each individual line and CCD based where (arrays of) CCDs are used to detect the light.

Advantages of optical emission spectroscopy

  • Simultaneous elemental analysis
  • Simple to use
  • Low detection limits (even to the sub-ppm level)
  • Excellent performance for light elements
  • Can be used to analyze inclusions in the material
  • Can in many cases replace (manual operated) combustion analysis

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