Wavelength selectors

The width of the band of radiation passing through a wavelength selector measured at half the band s height. 

A wavelength selector that uses either absorption, or constructive and destructive interference to control the range of selected wavelengths. 

Band of radiation exiting wavelength selector showing the nominal wavelength and effective bandpass. 

A wavelength selector that uses a diffraction grating or prism, and that allows for a continuous variation of the nominal wavelength. 

A device that allows all wavelengths of light to be measured simultaneously, eliminating the need for a wavelength selector. 

Stray radiation is the second contribution to instrumental deviations from Beer s law. Stray radiation arises from imperfections within the wavelength selector... 

Light from the broadband source is filtered by a wavelength selector and then passed into the sample container. If fluorescence occurs,... 

The ultraviolet (UV) absorption HPLC detector is basically a UV spectrophotometer that measures a flowing solution rather than a static solution. It has a light source, a wavelength selector, and a phototube like an ordinary spectrophotometer. The cuvette is a flow cell, through which the column effluent flows. As the mobile phase elutes, the chromatogram traces a line at zero absorbance, but when a mixture... 

In summary, the basic fluorometer, and thus the basic fluorescence detector, consists of a light source and a wavelength selector (usually a filter) for creating and isolating a desired wavelength, a sample compartment, and a second wavelength selector (another filter) with a phototube detector for isolating... 

A monochromator is a wavelength selector. It consists of two slits and a dispersing element in combination. The dispersing element splits the light from a source into the wavelengths of which... 

Fluorescence emission provides more selectivity and increased sensitivity compared to UV absorption. Basically, the instrumentation is composed of an excitation source, an excitation-wavelength selector, a flow cell, an emission collector, and an emission-wavelength selector. Due to their highly collimating nature, lasers are utilized as sources (He/Ne, diode, argon ion). The diode laser seems the best choice. 

Fig. 9.1 General arrangement of spectroscopic absorption/fluorescence measurement A,-wavelength selector, X-light source, D-detector, R-recorder. Intensity of initial (Io), transmitted (I), or fluorescent (Ip) light is related to the concentration of the sample C...

Abstract The introduction of Raman spectroscopy into new fields has been driven largely by advances in the underlying technology. While the spectrometer is still comprised of a light source, a wavelength selector, and a detector, the improvement in functionality of each of these components has had dramatic impacts on areas where Raman was once thought impractical, if not impossible. In addition, esoteric techniques once confined to academic spectroscopy labs are now finding wide application. 

A wavelength selector—interference and absorption filters or a monochromator (prisms and diffraction gratings)—to isolate the desired emission line. 

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