Granulometric techniques

The granulometric technique therefore starts with the smallest opening possible. If this is smaller than the small spheres then no detail is present in the... 

The granulometric technique is interesting because it does not rely on the setting of a threshold value or use of a binary image. It therefore performs particle sizing in a way more familiar to the one used by the human eye and brain. 

Integrated Granulometric Techniques for Particle Swelling Characterization... 

Therefore, although the Coulter Counter method allows an accurate evaluation of particle volume diameter in inert media as checked by mass balance evaluation, in some cases it is not suitable to measure particle swelling. In these cases, the Coulter Counter method needs to be integrated with other granulometric techniques. 

The same type of observations could be made from granulometric analyses carried out with the help of small angle laser light scattering. This technique allows the observation of both the sub-miaonic PMFIS-CD particles and the much larger griseofulvin... 

More realistic and complex tlieories consistent with the quite complex nature of the phenomena involved in the DR of light were developed later. Experimental studies have shown that this technique is affected by particle size, granulometric distribution and the refractive index of the particles, which has an important role when the particle size is near the wavelength of the 1R radiation. Diffuse reflectance Fourier transform (DRIFT) studies in the FIR region allow detection of the skeletal spectra of materials, such as mixed oxide catalysts, pigments and metal halides. 

A variety of techniques are available for the characterisation of particle size distributions but, because of the large size distribution of solids in water and wastewater, no single analytical method can be used. Besides their physico-chemical properties (stability, settleability, etc.), heterogeneous fractions have interesting optical properties. This is the reason why optical methods take an important place among granulometric methods (Table 5). 

The granulometric analyses have been performed by using a Sympatec diffractometer that operates in a range between 0.90 and 175 pm. This technique is based on the incidence of a monochromatic laser beam through a non-reactive liquid carrying a suspension of the sample to be analyzed. To provoke the total dispersion of the samples in the non-reactive liquid, isopropylic alcohol was used to remove the electronic and Van der Waals forces between the particles. 

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