Streaming current analyzers

Equations 5.363 and 5.364 are valid only if the capillary radius is much larger than the thickness of the diffuse layer. A number of modifications were suggested in the literature to extend the theoretical consideration to narrower capillaries and porous plugs (see, for example, the review article by Dukhin and Derjaguin and the book of Hunter ). Measurements of the streaming potential, streaming current, and electrical conductance of plugs made of latex particles were performed and analyzed by van den Hoven and Bijsterbosch. ... 

It may be appreciated that electrokinetic phenomena are determined by electric properties at the plane of shear rather than at the real surface. In the following sections of this chapter, the relation between the measured property and is further analyzed. This is done for electroosmosis, electrophoresis, streaming current, and streaming potential. The sedimentation potential will not be discussed any further, because in practice this phenomenon does not play an important role. The electrokinetic charge density may then be derived from using the theory for the diffuse electrical double layer. 

Another example of the application of the principles of coulometric titrations to a continuous on-stream analyzer is the moisture analyzer developed by Kei-del.18 It illustrates one of the outstanding advantages of the coulometric generation of a titrant namely, an intermediate is produced as a titrant that would not be available in standard solutions. The principle of the moisture analyzer is to place a phosphoric acid solution between two closely spaced platinum electrodes (helically wound in a glass tube). When current is passed between the two electrodes, the water in the phosphoric acid is electrolyzed... 

Phosgene concentrations in the range of 0-10 p.p.m. can be monitored on the principle that a marked change in ionization current is produced by the formation of sub-micron size particulate matter in a gas stream. The number of particles formed from contact of phosgene with dimethylamine [2138] or diethylamine [1381] was correlated with the phosgene concentration using an automatic analyzer [2138]. 

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