Fourier transform spectrometer, and

Figure 3.4 shows (i) a line spectrum (one-dimensional dispersive spec-trographic record), (ii) a spectrometric record, (iii) an interferogram obtained by a Fourier transform spectrometer, and (iv, v) two- and three-dimensional double dispersive spectra recorded e.g. by Echelle spectrometers. In principle, all forms may be obtained by OES. 

When the development of dedicated i rared spectrometers for surface studies started some ten years ago, some of them were designed as more or less complete ellipsometers, which in principle are insensitive to the ambient gas phase molecules. Fedyk et al. detected CO adsorbed on an evaporated Cu film at 4 torr, while Golden et al. reported work at 100 torr. More recently, Burrows et used a Fourier transform spectrometer and the polarizer approach above to study the reaction-rate oscillations in the oxidation of CO on a large Pt polycrystalline foil at pressures up to one atmosphere. With this rapid FTIR spectrometer they obtained a time resolution of 0.6 s at a sensitivity of 5% of a full CO monolayer. 

A book dealing with instruments that have been developed by a community connected to both science and industry (termed the research-technology community ) has chapters on Fourier-transform spectrometers and liquid scintillation counters.309,310 Precision scientific instruments were produced by specialist manufacturers the growth of the instruments industry in Britain and France between 1870 and 1939 has been the subject of a book.311 Of the analytical instruments developed in the 20th century, the most widely used has been the pH meter, and its invention and marketing by A. O. Beckman has been described.312... 

Infrared Spectra. IR absorption spectra in the zeolitic framework vibration region (1400-400 cm-1) were recorded using a Nicolet MX-1 Fourier transform spectrometer and the conventional KBr disc technique. 

The infrared spectrum of methocarbamol (KBr disc) was recorded on a Nicolet 7199 Fourier Transform spectrometer and is presented in Figure 2. The principal absorption bands include... 

Non-dispersive multiplex spectrometers include Hadamard transformation spectrometers and Fourier transform spectrometers and are particularly useful for the case of very stable sources. In both cases the information, such as intensities at various wavelengths, is coded by a multiplex system, so that it can be recorded with a conventional detector. A suitable transformation is then used to reconstruct the wavelength dependence of the information. In Hadamard spectrometry use is made of a codation of the spectrum produced by recombining the information with the aid of a slit mask which is moved along the spectrum [66],... 

Fourier transformed infrared (FT-IR) spectra in transmission were recorded using a Perkin-Elmer 7200 Fourier transform spectrometer and KBr disk technique. 

In recent years, new schemes have been introduced in Raman studies, taking advantage of Fourier transform spectrometers and of lasers. For instance CARS techniques can now achieve nominal resolutions of 0.003 to 0.005 cm" with accuracies of 0.001 cm" or better. Unfortunately, these experiments are still limited to a small number of skilled laboratories. Nevertheless, joint works using both IR and Raman data are found now, Raman being especially usefnl for infrared inactive bands. 

Ram et al. [97Ram] have recorded the 1-0, 2-1, 3-2, and 4-3 bands of K Cl in emission with a Fourier transform spectrometer, and earried out Dunham analyses to obtain ly constants and mass reduced parameters. 

Filler monochromators are of use only for flame photometry. They make use of interference filters, which often have a spectral bandpass of a few nanometers or less. Multiplex spectrometers include Hadamard transform spectrometers and Fourier transform spectrometers, and are especially useful where very stable sources are needed. Hadamard transform instruments make use of a coding of the spectrum produced by recombining the information with the aid of a slit mask which scans the spectrum [48]. 

Fig.6.32. Fourier transform spectrometer and basic signals (Courtesy Ulf Litzen)...

When one consults a text book on Fourier transform spectroscopy in order to understand what the technique consists of, one invariably becomes exposed to intricate optical and mathematical relationships. I would like to answer the question "what is a Fourier Transform Spectrometer and what is Fourier transform spectroscopy by relating F.T. spectrometers and F.T. spectroscopy to more traditional instrumentation and techniques "... 

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