Laser Diffraction PSD Analysis | Technical Data

Laser diffraction method is widely used to confirm grain size. The reasons are as follows.

・ Wide dynamic range - from submicron to the millimeter size range
・ Rapid measurement…results generated in less than a minute
・ Reproducibility…large numbers of particles are sampled in each measurement
・ Instant feedback…monitor and control the particle dispersion process
・ Sample processing capacity…hundreds of measurements per day
・ Needless proofreading…standard sample using easy examination
・ Fixed technique…base on ISO13320(2009)

測定原理
the principle target

Laser diffraction measures particle size distributions by measuring the angular variation in intensity of light scattered as a laser beam passes through a dispersed particulate sample. Large particles scatter light at small angles relative to the laser beam and small particles scatter light at large angles, as illustrated below. The angular scattering intensity data is then analyzed to calculate the size of the particles responsible for creating the scattering pattern, using the Mie theory of light scattering. The particle size is reported as a volume equivalent sphere diameter.

光学特性
optical properties

General laser diffraction system is organized 3 main elements.

光学ベンチ optical bench

A dispersed sample passes though the measurement area of the optical bench, where a laser beam illuminates the particles. A series of deterctors then accurately measure the intensity of light scattered by the particles within the sample for both red and blue light wavelenghts and over a wide range of angles.

試料分散ユニット sample dispersion units

Sample dispersion is controlled by a range of wet and dry dispersion units. These ensure the particles are delivered to the measurement area of the optical bench at the correct concentration and in a suitable, stable state of dispersion.

計測機器ソフトウェア instrument software

The Mastersizer 3000 software controls the system during the measurement process and analyzes the scattering data to calculate a particle size distribution. It also provides both instant feedback during method development and expert advice on the quality of the results.

レーザー回折式測定において考慮すべき事項
consideration in laser diffraction measurement

Sample and sample preparation dependent. Accuracy defined for the measurement of monomodal latex standards. This specification accounts for the manufacturer’s uncertainty in the latex size. Sample and sample preparation dependant.

provided by：Malvern Panalytical

Laser Diffraction Particle Size Analysis