Scanning grating monochromators

A dispersive element for spectral analysis of PL. This may be as simple as a filter, but it is usually a scanning grating monochromator. For excitation spectroscopy or in the presence of much scattered light, a double or triple monochromator (as used in Raman scattering) may be required. 

Near-infrared Spectroscopy for Process Analytical Technology 119 5.3.2 The scanning grating monochromator and polychromator diode-array... 

In this section the mainstream NIRS technologies in current widespread practical use for PAC applications will be examined. These are scanning grating monochromators, grating polychromator PDA spectrometer, AOTF analysers and FTNIR analysers. 

Three major advances have moved the technique closer to equal utility with chromatographic methods for release testing. The first advance was the development of suitable hardware. While useful for food and agricultural products, early interference type filter instruments and scanning grating monochromators were neither sensitive nor quiet (instrument noise, not operating noise) enough for certain pharmaceutical applications. The development of stable, sensitive, and precise... 

Fluorometry and Phosphorimetry. Modem spectrofluorometers can record both fluorescence and excitation spectra. Excitation is furnished by a broad-band xenon arc lamp foUowed by a grating monochromator. The selected excitation frequency, is focused on the sample the emission is coUected at usuaUy 90° from the probe beam and passed through a second monochromator to a photomultiplier detector. Scan control of both monochromators yields either the fluorescence spectmm, ie, emission intensity as a function of wavelength X for a fixed X, or the excitation spectmm, ie, emission intensity at a fixed X as a function of X. Fluorescence and phosphorescence can be distinguished from the temporal decay of the emission. 

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