Steel Chemical Test by spectrometer :- Optical Emission Spectroscopy is the measurement of elemental wavelengths by “sparking” the material. A metallic sample is placed on the unit, and the machine creates a plasma burn on the surface of the sample. The compositional elements are excited through the burn process and give off different wavelengths of light. Each separate element’s wavelength is read by the Spectro machine and reported for Alloy Determination.