Particle size analysis using non-invasive dielectric sensors

16 Particle size analysis using non-invasive dielectric sensors 

The use of capacitance measurement is based upon the principle that the concentration changes as particles settle through a suspension and will alter the effective dielectric constant between the sensing electrodes. A complete capacitance transducer consists of capacitance sensing electrodes together with capacitance sensing electronics, which is essentially a capacitance to voltage converter. 

The analyzer described by Simons and Williams [65] consisted of an array of eight pairs of capacitance electrodes mounted vertically down the side of a sedimentation tube of length 26 cm and diameter 2.5 cm. The electrodes were embedded in acrylic and flush mounted to the inside wall of the tube. 

Soda glass spheres at a volume concentration of 1.65%. in size ranges frc m 20 to 60 f.im and 2 to 18 pm, gave re.sults comparable with Andreasen and El/.one. 

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