Extinction methods

Although there is no doubt that the particle extinction method is superior to classical reflection/transmission techniques for determining the effective complex index of refraction of coal, it is more suitable for spherical particles rather than irregularly shaped particles. For coal and char particles, it is very likely that material and shape nonhomogeneity will affect the results obtained in experiments. Therefore, the particle extinction technique can be used to obtain average index of refraction data for coal particles. 

When applied to part of a glass container this word means that that part is too thin e.g. Light Shoulder. Light-extinction Method. See... 

Statistical Extinction Method for the Inline Monitoring of Particle Processes... 

Abstract The object of this study is to develop a particle measurement system on the basis of the Statistical Extinction Method, which provides an inline monitoring of different particle processes. The Statistical Extinction Method determines from the mean value and root mean square deviation of a transmission signal through a particle collective, a mean particle size and a particle concentration. For the determination of particle size distribution, an advanced Statistical Extinction Method is developed and verified. This method requires the measurement of transmission signals of several light beams of different beam cross sections through a particle collective. 

The determination of a mean particle size according to the Statistical Extinction Method provides several requirements to the geometry of the light beam in the measurement volume. In this work, different optical concepts of Statistical Extinction Sensors generating different beam shapes in the measurement volume are developed. 

The Statistical Extinction Method (SE-Method) is an optical and thus noncontact method for the determination of mean particle sizes and particle concentrations of particle collectives. The measurement system calculates the particle size and their concentration from the extinction of a light beam, which illuminates a well-defined measurement volume of the collective. The Lambert-Beer law provides the interrelationship between the extinction E(x, c. A, ni) of the light beam and the particle size X plus their number concentration in the spray [5, 6] ... 

In this work, two optical particle measurement systems, on the basis of Statistical Extinction Method, have been developed. The Statistical Extinction Sensor (SE-Sensor) determines a mean particle size and a particle concentration inline in particle processes. Eor this purpose, the temporal course of the transmission of a light beam through the particle collective is measured and the mean particle size and the concentration are determined according to the Statistical Extinction Method (SE-Method). The PSD-SE-Sensor measures the temporal course of the transmission of nine light beams with different beam cross sections and determines a particle size distribution and concentration according to an extended Statistical Extinction Method (PSD-SE-Method). 

Dannigkeit, F., Steinke, L., Ripperger, S. (2012). Basic preeximinations of inline monitoring of process sprays by statistical extinction method. Particle Particle Systems Characterization, 27, 137-145. 

The theory of extinction methods has been well described by Troelstra As a very simple example we shall treat the case of a white sol (in which light is scattered but not absorbed) and where the particles are so small that Rayleigh s law holds accurately Moreover we assume that the multiple particles formed during the coagulation scatter as much as a massive spherical particle of the same weight. 

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