Dispersive spectrometers, optical principles

To establish a quantitative basis for comparing the performance of dispersive and FT spectrometers, it is necessary to review first the optical principles governing the operation of each type of instrument. The primary purpose here will be to... 

Dispersive spectrometers. For a long time, mid-IR spectrometers were constructed on the principle of the double beam design. This fairly complex optical assembly, which remains in use for the UV/Vis, yields progressively over real time the... 

Conventional IR spectrometers follow the same principles as described for UV/vis spectrometers, but, bearing in mind that IR radiation is basically radiant heat, the detectors are usually sensitive thermocouples and the monochromator/spectrometer optics must be adapted to transmit in this spectral region. Samples are frequently prepared as thin films or solid dispersions between IR transparent optical surfaces (KBr discs, etc.). 

The principles and operation of UV /VIS spectroscopic detectors are discussed at length in Section 5.2.4. The detector in HPLC refers to the whole spectroscopic assembly, whose design is optimized to make rapid, continuous measurements of solutions passing through a flow cell of volume much smaller than the typical sample cell or cuvette of a conventional spectrometer. The light source, optical train, dispersion device, and light detectors are similar in design to those discussed in Chapter 5, but they are often built on a... 

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