Prisms materials for

The material of the prism is important in infrared spectroscopy, since it must be transparent to infrared light. The material most frequently used for analysis in the middle wavelength region is sodium chloride. Prism materials for the analysis of short and long wave infrared light are usually potassium bromide, cesium bromide, and cesium iodide. 

The free spectral range of a spectrometer is the wavelength interval 8X of the incident radiation for which a one-valued relation exists between A and the position x(A) of the entrance-slit image. While for prism spectrometers the free spectral range covers the whole region of normal dispersion of the prism material, for grating spectrometers SX is determined by the diffraction order m and decreases with increasing m (Sect.4.1.3). 

Internal reflectance (attenuated total reflectance ATR ). The internal reflectance or, more usually, attenuated total reflectance (ATR), technique depends on the total reflectance of an IR beam at the internal face of an IR-transparent crystal of high IR refractive index, as shown in Figure 2.38. Medium 1 is a prism of such a material (for example, Si, Ge or KRS-5 [thallous bromide- iodide]), medium 2 is a thin coating of a metal (Au, Pt, Fe) which forms the working electrode and medium 3 is the electrolyte. The... 

Fluorite is highly valued as a flux in the manufacture of steel also as a raw material for hydrofluoric acid. When of optical quality, the mineral is used for lens and prisms in scientific instruments. 

Application was carried out by soaking the stone material for one minute. Two samples of each variety of stone remained untreated. The prisms were exposed at six different sites in Germany (among them Dortmund and Duisburg) covering a wide range of climatic and immission situations. One set of samples was stored in the laboratory for comparative investigation. 

Calcium fluoride occurs naturally as the mineral fluorspar, and is commercially important as the raw material for the manufacture of HF (equation 11.6) and F2 (see Section 16.2). Smaller amounts of Cap2 are used as a flux in the steel industry, for welding electrode coatings, and in glass manufacture prisms and cell windows made from Cap2 are used in spectrophotometers. 

Bom in Scotland, William Nicol (1768-1851) was a professor at the University of Edinburgh. He developed the first prism that produced plane-polarized light. He also developed methods to produce thin slices of materials for use in microscopic studies. 

Why is glas heller than fused silica as a prism ctmsiruclion material for a mono-chroinaior io be used in the region of 400 o SIX) nni ... 

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