Spectrograph prism based

Figure 13.13 Spectral image of a cross-sectioned photographic film recorded using a prism-based PA IR spectrograph coupled to an infrared microscope. Reproduced with permission from Ref [8].

Names such as spectrometer, spectroscope, spectrograph or monochromator are used for basically the same types of instruments, which are, however, applied in different ways. The principle of a prism spectrograph is illustrated in Fig.6.17. The resolving power is determined by the dispersion, dn/dA, and the length of the prism base b... 

Adam Hilger, Ltd., of London has an RU raies ultimes) powder mixture of 50 elements. The concentrations are adjusted so only the persistent spectral lines (raies ultimes) will appear when the sample is excited in a dc arc. The base material for the RU powder is a mixture of zinc, magnesium, and calcium oxides. A spectral plate of RU powder with the iron spectrum included is shown in Figure 7-5. The plate was obtained using a prism spectrograph, so the dispersion is not linear. 

Adam Hilger, Ltd., has such charts prepared for its RU powder standard. The charts were made with a prism spectrograph and thus the dispersion is nonlinear. Six separate enlargements, each 10 in. long, cover the spectral region from 2440 to 6717 A. Each chart includes an iron spectrum, RU powder spectrum, and a spectrum of the base material. All persistent lines of the 50 elements in the RU powder are identified and frequent identification of wavelength is included. The spectra were obtained using dc arc excitation. 

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