Multiple monochromators

Double and Multiple Monochromators. If monochromatic light of very high purity is required, it is often necessary to use two or several monochromators in series, such that the exit light of the first one becomes the entrance light of the second. The reasons for using such complex optical arrangements are two-fold. 

Dispersive spectrometers usually achieve this end by employing double or triple monochromators. Each monochromator distributes stray radiation of about 10 of the power of the exciting radiation over the entire spectrum. Consequently, sequential spectrometers for the scanning of Raman spectra employ multiple monochromators, i.e., double or even triple monochromators with additive dispersion (Fig. 3.5-1 a). 

Monochromator 663, 791 Monodentate ligand 51 Morphine (and codeine) D. of (fu) 740 Mortar agate, 155 mullite, 155 percussion, 155 synthetic sapphire, 155 Muffle furnace 97 Multielement analysis 174, 184, 775 Multiple range indicators 268 Murexide 316... 

The diffraction grating monochromator is a specific example of mnltiple beam interference effects. Interference between multiple beams can be generated by both division of amplitude (as in the Fabry-Perot interferometer) or by division of wave front (as in the diffraction grating). (Figures 5.9 and 5.10)... 

The monochromator can be replaced by a polychromator. In this instance, a plate with multiple slits is placed at the focal point of the entrance slit to collect the selected lines of radiation. A detector is placed behind every slit (Fig. 15.5). This optical set-up is fixed since there is no rotation of the grating. 

Multiple activation of zinc sulfide is also possible. Zinc-cadmium sulfide, doubly activated with silver and gold, which is used as a white-luminescing, one-component phosphor for monochromic cathode-ray tubes [5.334], and the yellow-luminescing ZnS Cu, Au, A1 phosphor, whose emission color corresponds to that of Zn, x Cdx S Cu [5.332], are known. 

The diffraction grating monochromator is a specific example of multiple-beam interference effects. Interference between multiple beams can be generated by both division of... 

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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