Ultrafine Particle Size Distribution Analyzer

A new microscopic image processing and analyzing system is introduced in this paper . In this system , microscopic technology , CCD technology , A/D technology and processing technology of digital image have been used . Using the instrument , we have succeeded in measuring and analyzing the diameter of ultra-fine particles .Working principles of the system can be recited as follows . Samples on the objective table are illuminated by the light. They image a frame of real image when beams pass the objective . The photonsensitive surface of CCD receives the image and transform it into charge signal . Then image collecting card collects the charge signal and transform it into digital image . The digital image can be displayed on the screen of a computer . Then we can adjust the microscope according to its definition and selectly collect image of different fields of the same sample . Using our software to process the digital image , we get the size of the fine particles and the Stat. Curve of the particle-size distribution . In the end ,we get the analyzing results in forms of report.The software was written in Visual C++ . It includes two modules , the collecting module and the analyzing module . In the software , we average the random noise of the system and substract the background from the whole image . We demarcate the magnification of the system by some standard rectangular grating and we select dispersant to abate the influence of Brown motion.After having made experiments many times , we find that the repeatability of the system is satisfactory. It is reviewed that we have realized the important change from subjective to objective in analyzing ultra-fine particles and improved the reliability of the results .