0/45-degree reflectance measurement

Color. The visual color, from white to dark brown, of sugar and sugar products is used as a general indication of quaUty and degree of refinement. Standard methods are described for the spectrophotometric deterrnination of sugar color that specify solution concentration, pH, filtration procedure, and wavelength of deterrnination. Color or visual appearance may also be assessed by reflectance measurements. 

The selection of continuous over-batch processing is driven by two factors economics and control [1]. Hitherto, this discussion had largely focused on the former. Continuous processes inherently require a greater degree of measurement and control (Section 14.4), a reflection of the shorter timescales over which process or product manipulation must be made in order to assure that intermediate and product streams remain to specification. 

In addition to reflectance measurements, the pellets were studied microscopically employing a gypsum plate. This is one of the most effective ways of observing coke differences without relying on mechanical measurements. The appearance of the various constituents of the coke, whether flat, mottled or striated and the degree of anisotropy readily indicated the type of coal from which the coke is produced (1). Utilizing the gypsum plate, microscopically this natural coke appeared striated and anisotropic. Production coke from a low volatile coal has this same appearance. 

When reflectance measurements are carried out on opaque or translucent food materials, a number of problems exist in the seleetion and preparation of the samples. The first is that simply by reason of its presentation method, the sample area as presented to the instrument may not be representative of the bulk of the material rmder test. Most instruments in common use are designed to accommodate samples whieh are flat, and therefore reflect light from one plane only. Most food materials are not flat and some degree of compromise has to be made in order to ereate viewing areas whieh are. It is often the case that it is advantageous to deliberately ehange the sitrface characteristics of the sample in order to enhanee eolom differenees between specimens. Andre and Pauli (1978), for example, pitlverised dehydrated pasta into a powder and then tabletted the powder for eolom measurement in order to minimise variation caused by differenees in the shapes and surfaee properties of commercially available produets. 

Lasentec MIOOC Particle Geometry Monitor. The Lasentec MlOO monitor uses an FBRM (Focused Beam Reflectance Measurement) technique to measure the rate and degree of change to the particle population and Particle Geometry (a function of the shape and dimension of the particles and agglomerates as they naturally exist in... 

The posterior distributions do however not produce a total measure of imcertainty. The assessments are based on a set of assumptions and suppositions and these could hide or camouflage imcertain-ties. Consider for example the use of historical data for stuck-pipe downtime. In the probabilistic analysis we assume that the data are representative for the operations analysed. But the data used could to varying degree reflect the actual operations. There is considerable arbitrariness in the filter adopted to generate the input data of the analysis. The result is that we may experience surprising outcomes relative to what are expected from the probabiUstic analysis. 

There have not been many systematic studies of the degree to which the surface of a polymer is diffuse on this scale, although neutron and x-ray reflectivity measurements are sensitive enough to provide this information. What observations exist are consistent with an interface whose width is about 5... 

Optical Properties. Brightness, or visual whiteness of paper, can be defined as the degree to which light is reflected uniformly over the visible spectmm. Since pulp and typical impurities tend to be yellowish, blue dye is sometimes added in addition to appropriate fillers. The percentage reflectance is usually measured in the blue end of the spectmm at or near 457 nm (14). 

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