不扩束激光粉尘粒度分布测试系统的研究

【作者】 王荣；

【导师】 卞保民；

【作者基本信息】 南京理工大学 ， 测试计量技术及仪器， 2004， 硕士

【摘要】 本文以江苏省激光研究所委托“超高浓度粉尘检测报警装置”项目为背景，研究用不扩束激光进行粉尘粒度分布在线测量的方法，从理论和实验两方面都进行了一些探索。 首次提出采用不扩束激光的颗粒群衍射光强分布信号测定粉尘粒度分布的新思路，从理论上证明了颗粒群的衍射光能量角分布在时间累积和空间累积上的等效性。在此基础上，改进了传统的前向光散射角分布测试方法，建立了不扩束激光粉尘衍射光角分布实验测量装置。该装置避免了由于光源的扩束而带来的杂散光以及系统体积增加等问题，提高了信号的信噪比，大大减小了测试系统的体积，使系统更加稳定可靠。针对目前国内粒度仪产品都只能对湿粉进行测量的问题，设计了粉尘发生器，直接对干粉测量，为现场的实时在线检测创造了条件。由于计算机和CCD技术的发展，光电检测的器件由高灵敏度的CCD面元替代传统的光电环靶，大大提高了测量的精度和速度。同时在消除主光束的影响及如何确定图像的中心方面做了一些有益的工作。更多还原

【Abstract】 The research of this thesis is based on the project "device for detection and alarm of ultra-high concentrate dust" that is supported by Jiangsu laser institute. The on-line detection technique for the particles distribution in radius without laser beam expansion is investigated in theory and experiment.A method for detecting the collective particles distribution in intensity by optical diffraction technique without laser beam expansion is first proposed. For the collective particles, the time-integration is proved equivalent in theory to the space- integration in the angular distribution of scattering optical energy. The conventional system for particles detection based on fore-scattering principle is simplified and some practical problems, such as the stray light induced by beam expansion and the volume increase, are resolved. In this way, the signal-to-noise ratio of this detection system is greatly increased and the corresponding volume is reduced. The stability of the whole system is enhanced. Due to the available particle detectors that can only measure wet dust, a novel dust generator is designed, which can be applied for dry dust detection on line. With the development of computers and CCD technique, the high-sensitive CCD surface has substituted the conventional photoelectric circle surface as the photoelectric detector, which leads to the distinct increase in both accuracy and speed. Besides, how to eliminate the main light influence and determine the center of recorded images are also studied in detail.更多还原