BT-9300HT particle size analyzer is a high performance particle size distribution analyzer with the functions of auto alignment, auto water suction, auto water level measurement, auto dispersing, etc., which adopts semi-conductor laser that has features of high power, long lifetime and good monochromaticity; specially designed photodetector array of large size and high sensitivity which is made by large scale integrated circuit technique; two sample feeding ways which are peristaltic circulation pump and small volume cell assembly; whole process of Mie theory and processing mode of multiple distribution models; a series of advanced technologies and manufacturing techniques which are high precision data transmission and processing circuit and so on, to make the instrument has outstanding features of accuracy and reliability, fast test speed, good repeatability, easy operating and so on. It is a new generation of particle size test instrument which integrates laser technology, computer technology and photoelectron technology.