Principle sedimentation sedimentation (sedimentation size analysis) is based on the particles in the suspension system, the particles themselves neutral (or suffered centrifugal force), suffered buoyancy and viscous resistance of the three balance, and viscous forces obey the principle of Stokes to implement the determination, in which case the particles in the suspension system of the settlement at a constant speed, and the sedimentation rate is proportional to the square of the particle size. Notably, only to meet the following conditions in order to measure the particle size using the sedimentation method; particles should be close to spherical shape wanted, and the liquid was completely wetted; settling velocity of the particles in the suspension system is slow and constant, but reaches a constant velocity time is short; the particles in the suspension system of the Brownian motion does not interfere with its settling velocity; the interaction between particles does not affect the settlement process. Determination of particle size of sedimentation divided into gravity settling and gravity settling two centrifugal sedimentation method, gravity settling adapted particle size of 2 to 100 ?? m particles, and a centrifugal sedimentation method is adapted to a size of 10 ?? m ~ 20 ?? m particles. Due to centrifugal particle analyzer uses the principle of Stokes angle of water droplets plant sales, so the analysis is to obtain an equivalent particle size, particle size distribution for the autumn equivalent weight average particle size distribution. Generally suitable for high-speed centrifugal sedimentation particle size analysis of materials Nali. The method is now more accepted extinction sedimentation method, due to the different particle sizes in the suspension system, the settling velocity is different from the same depth of particle settling time is different, and therefore, the density at different depths in the suspension droplets will exhibit different changes angle manufacturers, according to the measurement beam passes through the optical density of the suspension system can calculate the particle size distribution. The advantage is to measure the mass distribution. The advantage is a measure of the mass distribution, strong representation droplets angle, comparing the test results with the instrument is good, the price is relatively cheap. The disadvantage is that the small particles for test speed slow, poor reproducibility; non-spherical particles of error, it is not suitable for the mixed material, the dynamic range is narrower than the laser diffraction method. Currently Zetasizer more to 500 ~ 700nm wavelength laser as the light source, therefore, the first community-type particle size analyzer for particle size at 5 ?? m or more accurate results, but for less than 5 ?? m diameter particles Michaelis is using a mathematical correction. Therefore, the measurement of sub-micron and she nanoparticles have some errors, even difficult to accurately measure. For the scattering of laser particle size analyzer, the direct scattering of scattered light information collected for processing, so that she was able to accurately determine the sub-micron and nano-sized particles, while the size of the particles larger than 5 ?? m concerned, scattering Zetasizer you can not come up with accurate measurements. Laser light scattering method can measure the particle size distribution of 20 ~ 3500nm, access to the equivalent spherical volume distribution, measurement accuracy, speed, angle measurement representative price drops strong, reproducible, suitable for measuring the mixed materials. The disadvantage is the requirement for the high detector, compare the difference between each measurement instrument. Photon correlation spectroscopy method can measure the range of 1 ~ 3000nm particle size distribution, particularly suitable for ultra-fine particle size analysis of nanomaterials. Measuring the volume of distribution, high accuracy, high speed, wide dynamic range, you can study the stability of the dispersion system. The disadvantage is not suitable for fast sample size distribution measurement. Droplets corner where the good, high-City droplets angle, ShengDing instruments provided by the Dongguan Sheng Ding Precision Instrument Company. Dongguan Sheng Ding Precision Instrument Co., Ltd. (www.dgshengding.com) strong, credible, in Dongguan, Guangdong specialized instrumentation industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead ShengDing instrument and you hand into the brilliant, for a better future!