【作者】 陈钊；

【导师】 郭永彩；

【作者基本信息】 重庆大学 ， 光学工程， 2003， 硕士

【摘要】 由于目前工农业生产中对颗粒粒径测量的需求相当活跃，研究各种粒径测量技术和开发各种粒径测量仪的重要性很突出，国内的研究水平和仪器制造技术的成熟度与国外的发展水平相当。现阶段，基于各种测量原理的颗粒测量技术比较多。其中，光学法测量粒径具有诸多优点，在颗粒粒径测量仪上获得了广泛的应用。重庆大学成功研制的针对喷雾场雾粒粒径分布的WL型测量仪，其技术水平走在了国内前列，但该测量仪的体积较大，现场使用和操作不便。因此，在该测量仪的基础上，研制微型化的雾粒粒径测量仪十分迫切。论文就是围绕着这个问题来展开的。微型化雾粒粒径分布测量仪的测量原理是米氏光散射理论，当不同粒径的颗粒被平行激光束照射后，发生光散射现象，散射光的参数包含有被测颗粒粒径的信息，但其数值计算量大且复杂。当颗粒粒径满足一定条件时，米氏光散射可以用夫琅和费衍射来近似。因此，只要测量出不同角度的衍射光能量，在理论上就可反演出颗粒的粒径分布。针对不同的颗粒群，可以使用不同的分布函数去逼近被测颗粒的粒径分布，其中，比较常用的是双R-R分布函数。或者，使用独立模式算法反演数据。测量仪器采用的光路直接影响仪器的结构尺寸，接收透镜和采样区位置的关系具有不同的配置方案，由于雾粒粒径测量仪应用背景的限制，所采用的光路配置方案是被测颗粒位于透镜前方，光能接收器件位于透镜后焦面上。微型化雾粒粒径测量仪基于激光衍射法原理测量雾粒粒径的分布，应用分离式模块设计理念，优化设计过程，将测量仪在功能上划分为独立的三个部分，即起数据采集作用的探测器，数据处理、显示并存贮的PC机软件系统和连接探测器与PC机的转接头。探测器的设计是论文的重点和难点，是实现测量仪微型化的关键问题，其正确的功能划分和优化设计是实现微型化的保证。探测器的设计有：光学器件的设计和选取、电路的设计、采样区大小控制装置和防污染装置的设计。PC机软件系统的设计有：与探测器通讯、数据反演、数据库的设计等。在PC机和探测器之间巧妙地加入一个转接头，负责不同通讯协议的电气转换和为探测器提供电源。整个仪器结构紧凑、智能化程度较高，可在线、动态测量，能够适应各种恶劣环境的现场测量要求。更多还原

【Abstract】 The heavy demands of particles sizing in industry and agriculture are increasing rapidly at present, so it is very important to study techniques of particles sizing and develop measuring instruments. The research and development in this field in china is close to the euramerican. There are various measuring instruments based on different measuring principle. With a good many advantages, the light scattering technique of particles size measurement gains extensive applications. The atomized particle size measuring instrument modeled WL developed by Chongqing university is successful and keep head domestically ,but its volume is large and spot operation is discommodios Thus, it is necessary to study and develop miniature measuring instrument based on the WL instrument. This thesis is founded on the problem above.When various diameter particles are irradiated by a collimated laser light beam, light scattering phenomenon takes place, and the scattering light parameter include the information of the particles size distribution. Mie scattering theory is the fundamental principle of the particle size measuring instruments and its computations are complicate. When the diameter of the particles satisfied some conditions, Mie theory is approximate to Fraunhofer diffraction theory. Therefore, if different light energies with different angle are measured, the particle size distribution can be calculated in theory. Many distribution functions are employed to approach the particle size distribution, including Rosin-Rammler function in common use ,or the algorithm of independent model should do. The light route used by measuring instrument determined its volume, according to the place between sampling area and lens, with the application background limits, the miniature atomized particles size measuring instrument takes scheme that the sampling area locate in front of the lens and the optic-electronic sensor at the back focal plane of the lens.The miniature atomized particle size measuring instrument employs<WP=6>separated module ideas and is optimized. It can be divided into three parts: detector with data sampling function, PC software with data processing, displaying and storage function, they are linked with a connector. The detector design consists of design and select of optic parts of an apparatus, circuit design, sampling area control and antipollution device design. PC software include communication with detector, computing the particles size distribution, database and so on. The connector plays the role of transition of communication protocol and supply the detector with power. The design of the detector is key to realize the miniature, which is the emphases and difficulty in this thesis. Wholly, the miniature atomized particle size measuring instrument is tight and intelligent and it can be on-line dynamically measuring in a awful spot environment.更多还原