Optical emission spectrometry (OES) is a widely-used, industry-accepted technique to provide chemical analysis for both alloying and trace elements in metals. OES instruments can analyze any metal in many shapes and forms and are used for process and quality control, incoming materials inspection, and research and certification.
OES analysis is based on the ablation of sample material by high-frequency electrical sparks applied between a metallic sample and an electrode. The ablated material is excited in the argon plasma generated by the sparks and a corresponding light in the VUV-visible range is emitted. The emitted wavelengths are characteristic of each element and their intensity is proportional to the element’s concentration in the sample. The light emitted is directed towards the optical system. The main component of the system, the diffraction grating, separates the polychromatic light into its monochromatic constituents by dispersion over a certain wavelength range. The photons of the wavelengths of interest are usually detected with PMTs (Photo-Multiplier Tubes) and transformed into electrical signals. Alternatively the full spectrum or part of it may be collected with CCD detectors.
OES is a robust and reliable technology. Well established for the analysis of metals and alloys, OES is the most widely used technique in iron and steel, aluminum, copper, nickel, zinc, lead, tin, cobalt, titanium, magnesium, precious metals and specialty metals/alloys because the technique provides the fastest analysis of all the elements with high precision and accuracy. Sample preparation is fast and simple (paper grinding or milling). High throughput is routinely achieved (> 400 samples per day) with the lowest cost of ownership.
Advantages of OES
- Fast, robust, precise, stable and reliable technology
- Simplicity: Easy sample preparation
- Savings: Low capital investment and operating costs
- Range: From trace (sub-ppm) to alloy concentration levels
- Extremely fast and simple quantitative determination of all the elements needed (note: this is normally used for X-Ray) in pure metals and alloys in < 1 minute
- Unmatched technique for fast analysis of C, N, O, P and S in steel
- Ultra-fast analysis of non-metallic inclusions
- Primary metals production (Fe, Al, Cu, Mg, Ti, Au…)
- Metals processors
- Metals recycling
A variety of OES instruments are available to suit any application. Are you using one in your lab? Please tell us about your experience.