Temperature measurement absorptivity

Surface Area. The most important features influencing the performance of carbon blacks are aggregate size and surface area. Surface area is measured by gas- and Hquid-phase adsorption techniques, and depends on the amount of adsorbate required to form a surface monolayer. If the area occupied by a single-adsorbate molecule is known, a simple calculation will yield the surface area. A low temperature nitrogen absorption method, based on the original method of Bmnauer, Emmett, and Teller (BET) (30), has been adopted by ASTM as standard method D3037-86 (2). 

Several experimental techniques may be used, such as acid/base titration, electrical conductivity measurement, temperature measurement, or measurement of optical properties such as refractive index, light absorption, and so on. In each case, it is necessary to specify the manner of tracer addition, the position and number of recording stations, the sample volume of the detection system, and the criteria used in locating the end-point. Each of these factors will influence the measured value of mixing time, and therefore care must be exercised in comparing results from different investigations. 

Findlay, W. J., Zdrojewskl, A., and Qulckert, N. "Temperature Measurements of a Graphite Furnace Used In Flameless Atomic Absorption". Spectrosc. Lett. (1974), 7, 63-72. 

The absorption band of the colored form of spironaphthooxazine has been measured in thermal equilibrium with the spiro form, particularly in a polar solvent at low temperature. Typical absorption spectra of the colorless and the colored form in polymer fdms are shown in Figure 1.8. 

Pankove et al. (1985) measured the room temperature IR absorption spectrum of B doped Si that was passivated in an H2 plasma and found a band at 1875 cm-1 (Fig. 2). From a comparison of the observed vibrational frequency with typical values for B—H and Si—H bonds, it was argued that the H was attached to a Si atom in the B—H complex. It was further... 

EXAFS (Extended X-ray Absorption Fine Structure) measurements using synchrotron radiation have been successfully applied to the determination of structural details of SCO systems and have been particularly useful when it has not been possible to obtain suitable crystals for X-ray diffraction studies. Perhaps the most significant application has been in elucidating important aspects of the structure of the iron(II) SCO linear polymers derived from 1,2,4-triazoles [56]. EXAFS has also been applied to probe the dimensions of LIESST-generated metastable high spin states [57]. It has even been used to generate a spin transition curve from multi-temperature measurements [58]. 

Schoenung, S. M., and R. K. Hanson. 1981. CO and temperature measurements in a flat flame by laser absorption spectroscopy and probe techniques. Combustion Science Technology 24 227-37. 

Harwood, M. H and R. L. Jones, Temperature Dependent Ultraviolet-Visible Absorption Cross Sections of N02 and N204 Low-Temperature Measurements of the Equilibrium Constant for 2N02 N204, J. Geophys. Res., 99, 22955-22964 (1994). 

H2-H2. In contrast to the case of unmixed rare gases, pure molecular gases like hydrogen generally absorb radiation in the far infrared (and elsewhere) as is shown, for example, in Fig. 3.10, for three temperatures [37]. The data shown in the figure were obtained at gas densities from 10 to 100 amagats, but when the measured absorption coefficients are... 

Fig. 3.38. Absorption of N2-Ar in the fundamental band of N2 [111]. Nitrogen and argon densities were both 19 amagat room temperature measurement ( ) the solid line represents a fit based on the stick spectrum and a J-independent quadrupole transition moment. In pure nitrogen, an almost identical spectrum was obtained.

Fig. V-13. The absorption cross sections of the 02 continuum in the 1814 to 2350 A region, a is in units of 10"22 cm2 molec base e, at room temperature. The absorption cross sections are measured at minima between the well-separated rotational lines of the Schumann-Runge bands for X < 2025 A. a increases with pressure probably as a result of the formation of 04. The data are values at the low pressure limit. From Ogawa (755), reprinted by permission. Copyright 1971 by the American Institude of Physics.

The course of combustion reactions during flammation has been studied 78) by the application of gas analysis techniques 40), by absorption spectra 76), by temperature measurements during combustion 95, 133-135), and by the analysis of indicator cards 25, 99,110.112). 

Absorption—A physical mechanism in fibers that attenuates fight by converting it into heat-thereby raising the fiber s temperature. In practice the temperature increase is slight and difficult to measure. Absorption arises from tails of the ultraviolet and infrared absorption... 

---