Laboratory instrumentation spectrometer using conventional principles

The principle of emission spectroscopy used by spectrometers, emission spectroscopy (OES), is a technique used to examine and quantitatively analyze the constituent elements in materials. OES uses the fact that each element has its own unique yard structure. When absorbed into additional energy, each element emits light of a particular wavelength, or color. Because no two elements have the same spectral line. So the elements can be distinguished. The brightness of the emission spectral line is proportional to the amount of the corresponding element in the oil sample, so that the concentration of the element can be determined. In normal circumstances, before the excitation, each element's electrons are delivered to the oil or fuel at its lowest energy, causing the sample to vaporize. The electrons in the atom absorb energy and are temporarily forced to leave their elemental cores to reach a higher, unstable orbit. After this unstable state is reached, the electrons release the absorbed energy and return to the ground state or stable state. The energy released is a specific value that corresponds to the energy change in the electron transition in the excited atom. Energy is emitted in the form of light, and the secondary light has a fixed frequency or wavelength (frequency is inversely proportional to wavelength), which is determined by the energy of the electronic transition. Because many different electrons of some complex atoms may have many different energy transitions, many different wavelengths of light are emitted. These spectral lines uniquely correspond to the atomic structure of an element. The intensity of the spectral line is proportional to the concentration of the test element in the sample. If more than one element is present in the sample, spectral lines of distinctly different wavelengths will appear for each element. In order to identify and quantify the elements that appear in the sample, these spectral lines must be separated. Usually only one spectral line is selected among many possible choices to determine the concentration of an element. The selected line is generally brighter and can be protected from the spectral lines of other elements. In order to achieve this goal, an optical system is needed. All emission spectrum analyzer systems consist of three major components. They are 1) excitation source, 2) optical system, 3) readout system.