The Paschen-Runge Spectrometer

The slit position and its relation to the angle of incidence should be chosen to take advantage of the highest reflectivity of the grating. The spectral order desired also must be considered. Some Paschen-Runge spectrometers have two fixed slits. By using angles of incidence of about 20° and 50°, both 

FIGURE 4-12. Schematic diagram of the Paschen-Runge mounting for a concave grating. 

FIGURE 4-13. The Quantometric Analyzer. [Courtesy Applied Research Laboratories.] 

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