Page 10 - Shimadzu PDA-7000
P. 10

Principle of Optical Emission Spectrometry                                                                                Applications of Optical Emission Spectrometry






            In optical emission spectrometry, electrical energy is   values for several tens of elements within one minute of         The Optical Emission Spectrometer covers a wide analysis   components.
            imparted to a metal sample and the vaporized atoms are   starting analysis.                                               range from trace levels to high concentrations of metals –   It is used for process-control analysis and for raw materials
            excited to obtain emission spectra unique to the elements.   Shimadzu optical emission spectrometers use a unique         including steel, aluminum, magnesium, copper, zinc, lead,   delivery and product dispatch inspections in the metals
            These emission spectra are separated by a monochromator   process to obtain analysis results in just over ten seconds     tin, titanium, nickel, and cobalt – in ingots or alloy   refining and processing industries.
            and a detector (photomultiplier tube) detects the presence   after starting analysis. Optical emission spectrometers using
            and intensity of each for quantification and qualification of   photoelectric photometry are prescribed in the Japan      Ferrous Applications
            the elements contained in the sample. This analysis method   Industry Standards (JIS) and are adopted for a wide range of
            requires no complex pretreatment and obtains quantitative   official analyses.                                                          Steel
                                                                                                                                                    - Quality control by rapid in-furnace analysis
                                                                                                                                                     at each stage of manufacture
                                                                                                                                                    - Analysis for product standards evaluation
                                                                                                                                                    - Materials deliver inspections


                                                                                                                                                    Cast Iron
                                                                        Sample
                                                                                                                                                    - Quality control by rapid in-furnace analysis
                     Sample preparation   Analyzed sample surface                  Discharge spot                                                    at each stage of manufacture
                      (cutting, grinding)
                                                                                                                                                    - Analysis for product standards evaluation
                Diffraction   Monochromator                                                                                                         - Materials deliver inspections
                                                                                     Unknown sample intensity                         Non-ferrous Applications
                grating
                                                                       Electrode



                                                                                                     Content
                                                     Al                                 0.1  0.2  0.3  0.4  0.5  %                                  Aluminum Ingot and Rolling Industries
                                                                  Spectral Lines             Display                                          Al    - Quality control by rapid in-furnace analysis
                                                   PMT
                                                                                                                                                     at each stage of manufacture
                                                                                                                                                    - Analysis for product standards evaluation
                                                 Si                                                                                                 - Materials deliver inspections
                                               PMT
                                           N                                                                                                        Other Metals
                                                                                                                                                    - Quality control by rapid in-furnace analysis
                                         PMT
                                                                                                                                                     at each stage of manufacture
            Configuration                                                                                                                           - Analysis for product standards evaluation
                                                                                                                                         other      - Materials deliver inspections
            The PDA-7000 comprises the following parts:
            Excitation unit   The spark stand generates sparks between the sample and the counter electrode. Emission spectra of
                              the elements in the sample are introduced into the monochromator unit.                                  Machinery, Automobile, and
            Monochromator unit Splits the light into emission spectral lines. A sensor converts this light into electric currents.    Ship-building Applications
            Readout unit      Measures the generated photocurrents.
            Data processing unit Analyzes and processes the measured data.
                                                                                                                                                    - Analysis for product standards evaluation
                                          Monochromator unit                                                                                        - Materials deliver inspections
                         Printer                                   Concave diffraction  Monochromator unit  Spark stand
                              Data processing unit                 grating      Entrance slit   CRT/printer
                                                  Spark stand
                                                                                 Exit slit     Data processing unit
                                  PDA-7000                                                Excitation
                                                                                           unit  Interface
                                                                      Rotary oil pump  Photomultiplier
                                                                         Attenuator
                                                                          Integrator  A/D converter
                        Evacuation unit  Readout unit  Excitation unit                 Readout unit


                                                                                                                                                                                                                         PDA-7000 Series
      10                                                                                                                                                                                                                    Optical Emission Spectrometer  11
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