【作者】 孙亮；

【导师】 张涛；

【作者基本信息】 中国海洋大学 ， 控制理论与控制工程， 2010， 硕士

【摘要】 海洋是我国经济社会可持续发展的重要资源,海洋生态环境好坏与人类生存、生产、生活和健康息息相关。化学需氧量(COD)是海洋中有机物监测所采用的重要指标,也是海洋水质监测的一个重要参数,及时掌握和控制海水的COD,对了解有机物对海洋的污染情况有极其重要的意义。海水中COD的含量较低,测量方法要求灵敏度高,并且还要克服海水中大量的Cl-离子给仪器分析结果带来的影响。本文提出了利用臭氧氧化化学发光原理来测定海水的COD,采用LabVIEW软件成功研制了臭氧法海水COD分析仪。LabVIEW软件利用高性能的模块化硬件,结合高效灵活的软件,可以方便的进行仪器各种信号的采集以及处理工作,大大缩短了仪器的开发周期。海水COD分析仪具有现场、实时、快速、无二次污染的特点。本文主要介绍了COD分析仪的工作原理、硬件电路部分、软件部分和实验结论。COD分析仪以电解式臭氧发生器提供己知稳定浓度的臭氧作为氧化剂,化学发光方法作为检测手段,将所测得的光信号进行处理以后得到海水的COD值。硬件部分采用PC/104计算机作为仪器的核心,并通过编写的上位机软件对仪器进样系统、臭氧发生装置、数据采集和通讯等系统进行控制。通过中泰PM511P数据采集卡进行温度、光信号的调理和采集工作。本文软件部分采用LabVIEW图形化编程软件,并且重点介绍了信号采集的核心思想,使用了多线程技术提高软件性能,此外还介绍了自动测量模块、手动测量模块、数据通讯模块。通过现场对比试验检验了方法的准确度。仪器测量结果表明本仪器测量方法准确可靠、灵敏度高,仪器法与国标法的测定结果具有良好的线性关系,满足了海水COD测量的需要。更多还原

【Abstract】 Ocean is China’s important resources for the sustainable development of economy and society. The quality of the marine ecological environment is closely related to human survival, production, life and health. The chemical oxygen demand (COD) is an important index for monitoring the propagating of ocean organic substance, and is also an important parameter for monitoring seawater quality. It is essential to detect and control the seawater COD in time for understanding the marine pollution of organic substance.Usually the COD of seawater is relatively low, so a higher sensitivity is required for the measuring instrument. The influence of Cl" on the analyzer is also needed to be overcome.In this dissertation, the ozonaion chemiluminescence principle is used to determine the seawater COD, a COD analyzer based on LabVIEW is successfully developed finally. Using high-performance modular hardware and combining with efficient and flexible software, LabVIEW is convenient for signal acquisition and processing, which greatly shorten the development cycle of COD analyzer. This COD analyzer has many features such as in-situ, real-time, rapid, no secondary pollution.This dissertation describes the COD analyzer’s working principle, hardware, software and experimental results. The COD analyzer takes ozone with stable density, which is provided by the electrolytic ozone generator, as the oxidizer, and uses chemical luminescence as testing method to obtain the seawater COD value by processing the measured optical signals. The kernel of instrument hardware is PC/104 computer. The host computer software controls the sampling system, ozone generator, data acquisition and communication. PM511P data acquisition board is used to obtain and process temperature and light signals.LabVIEW, a graphical programming software, is used to program. The core idea of signal acquisition is introduced in detail. Multithreading technology is used to improve software performance.Automatic measuring module, manual measuring module, and data communication module of the COD analyzer are also introduced.The accuracy of this measuring method is examined by in-situ contrast experiments.The measuring results from both proposed method and national standard method are in good linear relationship, showing that this method is correct, reliable and sensitive, also can meet the needs of seawater COD measurement.更多还原