【作者】 王军强；

【导师】 王玉田；

【作者基本信息】 燕山大学 ， 测试计量技术及仪器， 2009， 硕士

【摘要】 石油对水资源的污染已成为主要的环境污染,由于饮用水资源极其有限,所以对水质实施及时的监测和污染处理就显得十分必要。基于荧光的分析法具有简便、检测灵敏度高、易于实现在线测量等优点,这使其已成为当前水中微量矿物油浓度监测的一个研究热点。本文对荧光测量法进行了详尽的研究,提出了一种在线测量系统的设计方法。论文从荧光测量的基本原理出发,研究了石油荧光检测机理、分析了荧光法和全光纤实现水中油浓度测量的可行性以及荧光法相对于现有国标采用的红外法的优点,为在线测量系统的实现奠定了理论基础。论文论述了吸收光谱、激发光谱、荧光光谱等荧光理论并通过实验的方法确定了矿物油的最佳激发波长和荧光波长。为激发光滤光片与荧光滤光片的选取提供了依据。研究了光源的光谱特性、光源的驱动电路设计、光纤的传输特性、光电检测器件的选择等。设计了荧光测量仪器的系统原理图、信号检测系统控制电路图并勾画了在线测量系统的工程架构。从工程实践角度讲,该设计具有很强的可操作性。通过对光纤荧光在线检测系统的噪声抑制方法进行分析,采用一种小波去噪方法——小波熵阈值去噪方法,进行小波阈值去噪,并将去噪后的荧光光谱图与用传统模拟低通滤波器去噪后的光谱图进行比较。结果表明,经小波去噪后的荧光光谱图更多地保留了原信号的信息,有助于提高系统的检测精度。更多还原

【Abstract】 Oil contaminated to water is serious environment pollution and the water resource is very limit to human, so it is very important that the quality of water is monitored and polluted water is processed.The analysis of oil in water base on the fluorescence is simpler and higher sensitive and easier in situ measurement. And because of this advantage, the fluorescence analysis became research hotspot in the concentration detection of oil in water.This paper research the fluorescence measure way and given a new in situ measurement system.Based on the fundamental theory of fluorescence measurement, this paper demonstrated the oil fluorescence detection principle and the feasibility of all optical fibers and fluorescence method in measuring oil concentration and also this paper describe the advantage of the fluorescence method compare with infrared method that was adopted by GB. All this can be used as the basis of theory and experiment for oil contamination measurement.The paper describe the absorption spectra and excitation spectra and the fluorescence spectrum properties and also selected the best excitation wavelength and fluorescence wavelength. All these were done for selecting excitation light filter and fluorescence filter.The paper studied the spectrum property of the excitation light, described the transmission property of fiber optic and selected photoelectric detector and so on. Described the blueprint of the fluorescence measuring instrument, design the control circuit of signal detection system and also described the system construction of the in situ measurement machine. It looked very suit for doing the real project.Through analysis and research of noise control for in situ detection system, we get a new method for wavelet de-noising that based wavelet entropy. And the de-noised fluorescence spectrum via the wavelet transformation using this threshold method is compared to the de-noised spectrum via the analog low-pass filter . The result shows that the de-noising spectrum via the wavelet transformation keeps more information for the original signa1.So the detection sensitivity of the system will be improved with the aid of this method.更多还原