Measurement of Concentration and Size Distribution of Particles Suspended in a Liquid by Using Attenuation of Laser Beam Propagation

A procedure and apparatus have been developed to determine the concentration and size of particles suspended in a liquid. A He-Ne Laser, nine kinds of powder samples and four kinds of liquid were used in the experiments. The values of attenuation caused by particles of suspension were proportional to the amount of particles existing on the optical pass of a Laser beam. The attenuation values calculated, according to calculation program developed by the authors, were agreed well with the experimental values. The attenuation values with suspension containing two kinds of powders corresponded to the sum of the product of the weight fraction and the attenuation values for the individual powder. The particle concentration of suspension and the mixing ratio of binary powders were determined by measuring the attenuation values. The measurement of attenuation for suspension at a fixed level was carried out during gravity settling, and the size distribution of the particles based on the number was determined by analyzing the change in the attenuation values over time.