The Research And Application Of Laser Particle Size Measuring System Based On USB Bus

Measuring particle size is to exhibit the particle size characteristics via special instruments and methods. Particle usually refers to micro solid, liquid, or gas material whose size is between several millimeters and certain microns, such as, metal powder, food, resin, pharmaceutical, pigment, cement, pottery, clay, catalyzer and other inorganic material, etc. It is so important to reflect particle size and distribution objectively and actually. The Laser Particle Sizer may obtain the information of particle size and distribution by detecting the relative energy scattered by the particles, with the fixed wavelength.At present, the data acquisition system in the LSA-ⅢLaser Particle Sizer developed by Tianjin University is based on ISA ,PCI,USB1.1 bus, using an optoelectric detector of 36 rings. In order to improve the measure range and the transfer speed of this system. This project implements the design of interface card based on USB2.0 bus with the special interface chip CY7C68013, using an optoelectric detector of 76 rings. It utilizes fully the characteristics of USB bus, for example, plug and play, hot plug and so on. The system can realize real-time acquisition, processing and displaying of data and provide a guarantee for the stability and reliability of Laser Particle Sizer measuring system.The main work includes:1. Designing the data acquisition hardware system of Laser Particle Sizer based on USB2.0 bus after knowing well such components as CY7C68013.2. Designing GPIF waveforms via GPIF Designer utility, realizing single-read transaction of data from the Laser Particle Sizer to the USB memory.3. Programming the USB firmware under the utility of Keil uVision2.4. Programming the USB device driver under the operating system of WIN2000.5. Improving the LSA software package and completing the experiment of real-time acquisition and displaying of data by using the new laser particle size measuring system.