Laser particle size analyzer, as a key equipment in the field of modern particle analysis, works based on the phenomena of light scattering and diffraction. Through a precise optical system and mathematical model, it achieves fast and accurate measurement of particle size distribution.

The core of laser particle size analyzer lies in the theory of laser scattering. When monochromeSexually excellentWhen the laser beam is irradiated onto the particles in the sample, the particles will produce scattering effects on the laser. The Mie scattering theory states that the propagation direction of scattered light forms an angle with the main beamθ， And the size of the θ angle is inversely proportional to the particle diameter - the larger the particle, the smaller the scattering angle; The smaller the particles, the larger the scattering angle. Meanwhile, the intensity distribution of scattered light is closely related to the number of corresponding particle sizes. Based on this principle, the instrument converges scattered light from different angles onto a multi-element photodetector array in the back focal plane by setting Fourier lenses in the optical path. The detector converts optical signals into electrical signals and transmits them to a computer for digital processing.

In the signal processing stage, the instrument uses complex mathematical algorithms to invert and calculate the raw light intensity data. By combining the Mie scattering theory or Fraunhofer diffraction model, and using optimization algorithms such as non negative least squares, the light intensity distribution data is converted into a volume or quantity weighted distribution of particles, resulting in a particle size distribution curveKey parameters such as D10, D50, D90, etc. This process requires precise setting of the refractive index of particles and media, as refractive index errors can lead to calculation deviations and directly affect the accuracy of measurement results.

To ensure the reliability of the test results, the laser particle size analyzer uses wet or dry dispersion techniques during the sample preparation stage. Wet dispersion utilizes the synergistic effect of mechanical stirring, high-frequency ultrasonic oscillation, and electromagnetic circulation pump to evenly distribute particles in the dispersion medium and avoid agglomeration; Dry dispersion achieves single-layer dispersion of particles through airflow. The instrument is easy and fast to operate, and the testing process only takes a few seconds to minutes. It also supports multiple sampling to filter out noise interference, significantly improving the repeatability of the test.

Laser particle size analyzer is widely used in chemical, pharmaceutical, mineral analysis, powder metallurgy, biomedical and other fields due to its high precision, wide measurement range and automation level, providing key technical support for the manufacturing, processing and research of particulate matter. With the continuous advancement of technology, its capabilities in nanoscale particle measurement and multi model joint inversion will continue to expand, promoting more industries to achieve intelligent upgrading of quality control.