BT-2001 particle size analyzer is a high performance particle size distribution analyzer. Dry dispersing system adopts Venturi dispersing effect by measures of shear, inertia, collision, etc, to ensure that the powders are in complete dispersing state when pass through testing zone. Even for the sample which is difficult to disperse such as NdFeB powder, it can be dispersed completely and also accurate test result will be acquired. It adopts photodetector array of large size and high sensitivity made by large scale integrated circuit technique which is specially designed, and it has high resolution and good accuracy; adopts whole process Mie theory and data processing mode of multiple distribution models; adopts a series of advanced technologies and manufacturing techniques including high precision data transmission and processing circuit etc., to make the instrument has outstanding features including accuracy and reliability, fast test speed, good repeatability, easy operating, etc. It is a new generation of particle size test instrument which integrates laser technology, computer technology and photoelectron technology.