紫外扫描式水质COD测量技术与仪器设计

【作者】 林桢；

【导师】 王晓萍；

【作者基本信息】 浙江大学 ， 光学工程， 2006， 硕士

【摘要】 本课题主要介绍了水质COD检测技术和仪器的发展、现状与趋势,为解决当前COD检测仪器存在的不足,创新性提出“紫外扫描式在线COD检测技术”,并成功研制成基于嵌入式系统的紫外全波段扫描式COD在线监测系统。该系统主要包括光学扫描系统,嵌入式微机系统与软件系统三大部分,是具有自主知识产权的新型快速、可靠、智能化、无二次污染的在线COD监测系统。 选取波长范围200～400nm的氘灯作为光源,利用平面光栅分光系统进行紫外全波段的扫描,得到紫外全波段的吸光度值。通过被测水样的大量实验,确定出被测水样的9个特征波长,并利用BP神经网络建立水样在特征波长处的吸光度值与COD浓度的相关性数学模型。实际测量时,将仪器扫描得到9个特征波长的吸光度,输入已建立的BP神经网络的数学模型进行反演计算,就可以快速得到被测水样的COD值。 论文第一章主要介绍了课题的研究背景与意义以及基本任务;第二章分析了当前COD测量技术与仪器的现状与特点,并提出了紫外扫描式多光谱COD测量技术;第三章详细介绍了系统的整体结构、光路扫描系统与硬件控制系统;第四章介绍了嵌入式系统的概念、特点,以及软件设计的流程、功能模块与调试分析;第五章介绍了神经网络的概念、建模与实验数据分析;第六章对课题进行了总结与展望,提出了改进的意见。更多还原

【Abstract】 We introduce the development of water COD measuring technique and instruments. In order to settle the deficiencies of the current COD measuring instrument products, we design a new measuring technique of ultraviolet scanning for water COD, and have developed the Ultraviolet Scanning COD online monitoring instrument based on embedded system successfully. This system includes three sections: optical scanning system, embedded microchip system and software system, which is a new type online COD monitoring system with the feature of fast speed high credibility intelligence and without secondary pollutions.We choose a deuterium lamp with the wavelength from 200~400nm as the light source, use a flat grate optical splitting system for ultraviolet scanning. Through a large number experiments of waste water, we get the sample’s nine absorbance at nine characteristic wavelength, and use the Bp neutral network to build the mathematic model. In actual measurement, we can get the COD level from the BP neutral network model build yet when we scan the reality sample in the instrument.In the first chapter, we introduce the research background and the basic task of this project. In the second chapter, we analyze the development COD measuring technique and the current instruments, design the new measuring technique of ultraviolet scanning. In the third chapter, we design the sections of this system, including optical and hardware system. In the fourth chapter, we introduce the concept and characteristic of embedded system, design the flow functional module and the debug analysis of software system. In the fifth chapter, we introduce the concept of neutral network, build the mathematic model, analyze the experiment data of various waste water. Finally we summarize the characteristics of our system and advance some improved suggests for the future.更多还原