Monochromator wavelength calibration spectral lines

Table I. Spectral Lines from External Sources Used for Monochromator Wavelength Calibration...

As mentioned previously (11), the wavelength position and stability of spectral lines from xenon or mercury excitation sources of spectrofluorometers may be variable with time-, and such sources are difficult to use with certainty for the calibration of monochromators. ... 

The tail of the plasma formed at the tip of the torch is the spectroscopic source, where the analyte atoms and their ions are thermally ionized and produce emission spectra. The spectra of various elements are detected either sequentially or simultaneously. The optical system of a sequential instrument consists of a single grating spectrometer with a scanning monochromator that provides the sequential detection of the emission spectra lines. Simultaneous optical systems use multichannel detectors and diode arrays that allow the monitoring of multiple emission lines. Sequential instruments have a greater wavelength selection, while simultaneous ones have a better sample throughput. The intensities of each element s characteristic spectral lines, which are proportional to the number of element s atoms, are recorded, and the concentrations are calculated with reference to a calibration standard. 

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