Monochromatic line

Monochromatic line absorption coefficient, (atm-m)" Gas absorption coefficient, m" ... 

Emission spectroscopy is used to measure concentrations of a wide range of elements. Complex mixtures of elements heated to high temperature display characteristic emission spectra composed of multiple monochromatic lines - the sum of the spectra of the individual elements. When the light is separated into individual spectral lines by the spectrometer, each element is represented by several lines and the pattern of these lines is unique to that element. The intensity of the light indicates the amount of an element present in the mixture. This principle provides for the quantitative recording of elemental abundance. 

Figure 5.2. Examples of spectra (left) and their corresponding interferograms (right) (a) two monochromatic lines of unequal intensity (b) small Gaussian line (c) broad Gaussian line.

Fig. 2.4 Instrumental Line Shape/LA(v) top), which is the Fourier transform of a boxcar function of unit amplitude extending from +A to —A. Fourier transform of an interferogram generated by a monochromatic line at vi = 2/A bottom)...

The spectrum of the heterodyne signal shows a Gaussian distribution around u = 0, because the difference frequency of the superposition of a monochromatic line profile with a Doppler-broadened profile gives a Gaussian profile around ty = 0. The spectral width is... 

Fig. 4.10. Intensity profiles of two monochromatic lines measured in the focal plane of L2 with an entrance slit width fx-X/a and a magnification factor /2//1 of the spectrograph. Solid line without diffraction dashed line with diffraction. The minimum resolvable distance between the line centers is A. 2 = flib/fx -X/a)...

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