Glass spectral transmission

Transmission. The spectral transmission of glass is determiaed by reflectioa at the glass surfaces and the optical absorption within the glass. Overall transmission of a flat sample at a particular wavelength is equal to (1 — R), where P is the absorption coefficient, t the thickness of glass, and... 

When radiation is incident on a translucent body, part of the incident radiation is reflected, part is absorbed, and the remainder is transmitted through the translucent body (Fig. 11.4). An example of a translucent body is a pane of glass. The relationship between the spectral reflectivity px, the spectral absorptivity ax and the spectral transmissivity Tx of the translucent body is... 

Figure 15 (A) Spectral transmission curves showing effect of glass type and thickness. (B) Transmittance curves of ampoules (61) and vials (62) used in original and subsequent Japanese photostability studies. (61) 20mL colorless ampoules (JIS R3512, No. 5), (62) 15mL colorless vials (N-16, Mamemu, Osaka). Source From Ref. 5.

The spectral transmissivity of low-iron glass at room temperature for different thicknesses. 

The variation of the spectral transmissivity of a 0.6-cm-thick glass window is as given in Fig. PI2-50. Determine the average transmissivity of this window for solar radiation (7 - 5800 K) and radiation coming from surfaces at room temperature (T 300 K). Also, determine the amount of solar radiation transmitted through the window for incident solar radiation of 650 W/m . 

The spectral transmissivity of a glass cover used in a solar collector is given as... 

FIG. 144. Spectral transmission of soda-lime-silica glass melted with an addition of 2%Fe203 (curve (7)— oxidation melting) and with 2%FeO (curve (2) — reduction, after Kocik and Nebfensky, 1962). 

Example 5.5 The spectral transmissivity of a 2.0mm thick glass sheet is approximated... 

Figure 9. Spectral transmission of calcla-alumlna glass fibers. Redrawn from F. T. Wallenberger, N. E. Weston and S. A. Dunn, Melt spun calcla-alumlna fibers infrared transmission, J. Non-Cryst. Solids, 12 [1], 116-119 (1990).

There is a large range of optical cells available for spectroscopy measurements and they vary in materials, size, shape, and spectral transmission characteristics. The most commonly used sample holder in fluorescence spectroscopy is a 10 mm x 10 mm x 45 mm volume cuvette made from fused silica (for UV to near-lR operation), glass (visible), or a plastic that is often polycarbonate and disposable. Of course, it is essential that the cuvette chosen is suitable for the application and experiment and that it is clean, and handled with maximum care. 

Nonetheless, near-IR is the most widely used IR technique. Less intense water absorptions permit to increase the sampling volume to compensate, to some extent, for the lower near-IR absorption coefficients and the inferior specificity of the absorption bands can for many applications be overcome by application of advanced chemometric methods. Miniaturised light sources, various sensor probes, in particular based on transmission or transflectance layouts, and detectors for this spectral range are available at competitive prices, as are (telecommunications) glass or quartz fibres. 

Crown glass has a refractive index of 1.51 in the visible spectral region. Calculate the reflectivity of the air-glass interface, and determine the transmission of a typical glass window. 

Figure 7.25 Examples of spectral sensitivities of a photodiode (a) and of two types of photomultipliers (b). The window transmissions are shown as q (silica) and g (optical glass). Horizontal axes, A in nm/100 vertical axes,

General Electric 4 watt germicidal lamp and a Corion Corporation 2537 interference filter (15% transmission at 2537). The Fluoromonitor s emission detection unit consisted of a RCA 931B (S-4 spectral response) photomultiplier tube and a Corning 7-51 glass filter that transmits light of wavelengths between 310 and 410 nm. 

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