Coulter distribution

Comparison of microscopic particle size distribution with the average distribution of four identical runs made with the Coulter Counter... 

A comparison of the distribution curves given by the Turbidimeter, Micromerograph and Coulter Counter for identical samples of tungsten is shown in Figure 20... 

H.L. Stalcup (Ref 28) evaluated the instru- -ment for the particle size determination of HMX used in rocket formulations. He found that Coulter Counter distribution was similar to that obtained with the Micromerograph except at the large particle end, where the Micromerograph indicated particles over lOOp compared to 32 p for the Coulter Counter. Median values were 13.5p by Micromerograph and 16 p for the Coulter Counter. The samples for the Coulter Counter were run on an as received basis, ie, while still water-isopropanol wet ... 

Perhaps the most useful method for determining particle distributions is that of electrical conductivity, the most widely used instrument is the Coulter Counter (named after the Inventors), although there are now other similar instruments on the market. Originally, this instrument was designed to measure blood corpuscles which are 2-8 p in size. It has proven to be very... 

The Coulter Counter is particularly usefiil and unique in that steps as small as 1.0 micron may be used if so desired. Results by this author have demonstrated that some distributions which appear to Gaussian may actually consist of more than one subdivision where the peaks are separated by only a few microns, an example is given as follows ... 

For a given bulk solid, determine particle size distribution, median particle diameter dv50 (e.g., using a Coulter Counter or a Malvern Laser Diffraction Analyser) and ps. 

By means of the Coulter channelizer 256 module an optional extra on the model ZM but built-in on the multisizer, enables biological cell-size distributions to be measured. This provides an ability to measure suspension... 

By using orifices of various diameters, different particle size ranges may be examined and the resulting data may then be combined to provide size distributions extending over a large proportion of the sub-millimetre size range. The prior removal from the suspension of particles of sizes upwards of about 60 per cent of the orifice diameter helps to prevent problems associated with blocking of the orifice. The Coulter Counter and the Elzone Analyser work on this principle. 

What is, perhaps, most disturbing is the assertion by Coulter and Fisher in 1985 that the ADRs from DPT should not have happened. They document that Japan switched to an acellular form of the DPT virus in 1981, which was just as effective in preventing the diseases but had fewer ADRs. Shoemaker reports that In Japan, the Ministry of Health, instead of trying to cover up problems with the vaccines, chose to find a solution." According to Shoemaker, it took almost 20 years for the United States to stop using the whole-cell version of the vaccine, and manufacturers are still distributing the whole-cell version in third-world countries "undoubtedly because it is cheaper to make." ... 

Coulter counter Miused. One leading manufacturer of microparticulate silicas prefers to ciMracterize the size distribution by the three ogives dit%, and dtt% W ch denote those particle diameters that represent the upper bound for 10,50, and 90% of tte total population, respectively. For instance, a powd having nominally 10 ftm particle size may be characterized by the ogives for the three percentiles as = 5.5 fim, dn%... 

Particle size distribution was measured with Coulter LS 230 laser equipment. Solids were determined with a drying scale. 

Other Measurements. Particle size distributions were measured by the Coulter Counter method. Absolute density measurements were made using the well known pycnometer method. 

Fig. 4.2.9 Histograms of the size distributions of the particles shown in Fig. 4.2.8. Original and final size distributions are shown by broken and solid lines, respectively. The diameter of an equivalent sphere having the same volume as a nonspherical particle was obtained with a Coulter counter. (From Ref. 9.)...

FIGURE 8.4 Cumulative size distribution of gelatin (lime-cured type B, bloom number 225) microparticles prepared at high pH obtained using a Coulter Counter and plotted as a log-probit function. (From Lou, Y. and Groves, M.J. (1995). J. Pharm. Pharmacol., 47, 97-102. With permission.)... 

Each port was located in an area of turbulence with the sampling tube directed into the flow so that small and large oil drops entered with equal facility. A Coulter Counter Model T -X 11 was used to measure the oil-drop size distributions. A Beckman Model 915A Total Organic Carbon Analyzer was used to measure oil concentration. 

Computer programs accounted for the presence of oil drops below- the detection limit of the Coulter Counter. The data processing procedure, which assumed that the oil-drop size distribution was lognormal, yielded accurate estimates of the true mean and standard deviation describing the emulsion drop size distribution. The data-analysis procedure did not affect the actual measured drop populations which were used in the kinetic studies. The computer programs are described in detail by Bycscda.8... 

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