基于psd的浓度检测系统设计与分析论文.doc

毕 业 论 文 基于 PSD 浓度检测系统设计与分析 学 院： 专 业： 学生姓名： 学 号： 指导教师： 摘 要 - I - 摘 要 目前，实时液体浓度检测技术相对来说还比较落后，因此研究新型的液体 浓度检测系统具有十分重要的意义工业生产中检测液体浓度的方法有比重法、 化学分析法、超声波法及光学法等但这些方法既费时又需繁琐的人工取采样， 滞后性大，无法实现实时检测液体浓度，鉴于以上问题，本文设计了一种 基于 PSD 的浓度检测系统 浓度的变化会引起液体折射率的变化，对于固定的入射光线，折射率的变 化会导致出射光线发生偏移，利用光电位置敏感器件检测出光线偏移量的大小， 进而得到液体的折射率，从而计算出液体浓度，再由 LED 显示出来本系统主 要由半导体激光器、双隔离窗光学系统、PSD 信号处理电路、基于 8051 单片 机的 A/D 采集运算控制电路和显示电路等组成双隔离窗光学系统采用两个隔 离窗使光线在待测液体中两次折射，测量结果更精确；PSD 信号调理电路主要 由前置放大、加法器、减法器和除法器等部分构成，将对信号进行 I/V 变换和 放大处理；基于 8051 单片机的 A/D 采集运算控制电路主要对 PSD 调理后的模 拟量信号转变为数字量，并将信号输入至单片机进行分析处理，从而得到浓度 值，最后由显示系统显示出来。

通过实验发现，光源强度和温度漂移对本系统的影响非常小，该系统具有 结构简单、稳定性好、灵敏度高、响应时间快以及自动化程度高等优点，能够 方便、准确地实现液体浓度的实时检测本浓度检测系统可广泛应用在化 工、制糖、食品、制药等诸多行业，是一种具有广阔发展前景的浓度检测系统 关键词：位置敏感器件（PSD） ，半导体激光器，液体浓度，8051 单片机 ABSTRACT II ABSTRACT At present, real-time on-line liquid concentration detection technology is still relatively backward. Research of a new type of liquid concentration detection system is of great significance. The proportion of liquid concentration detected in the industrial production method, chemical analysis, optical method. However, these methods are time-consuming and tedious manual to take sampling lag, can not achieve real-time online detection of the liquid concentration, in view of the above problems, this paper designs a new type of concentration detection system based on position sensitive detector. In the chemical and pharmaceutical, light industry and beverage and environmental protection departments and the various fields of scientific research and national defense are to detect and control the parameters of the liquid concentration. At present, the proportion of liquid concentration detected in the industrial production method, chemical analysis, ultrasonic and optical method. However, these methods are time-consuming and tedious manual to take sampling lag, can not achieve real-time online detection of the liquid concentration, in view of the above problems, the designs a new type of concentration detection system based on position sensitive detector. Concentration change can cause the change of liquid refractive index, the fixed incident light, the refractive index change will cause a shift of the emergent light, using photoelectric position sensitive device detect the size of the deviation of the light, the refractive index liquid is obtained, to calculate the liquid concentration, displayed by LED. This system is mainly composed of semiconductor laser window, double isolation optical system, PSD signal processing circuit, based on 51 single chip microcomputer A/D acquisition operation control circuit and display circuit, etc. Double isolation optical system consists of two separate window bends light after two, make more accurate measurement results; PSD signal disposal circuit is mainly composed of preamplifier, summator, subtracter and divider and other parts, will be the signal I/V transform and processing to enlarge; Based on 51 single chip ABSTRACT III microcomputer A/D sampling operation control circuit mainly of PSD after analog signals into digital quantity, and will be treated as signal input to the MCU is analyzed, the density is obtained, finally displayed by the display system. Experiments found that light intensity and temperature drift of this system is a very small effect, the system has simple structure, good stability, high sensitivity, fast response time and high degree of automation, etc. The liquid can be realized conveniently and precisely, and real-time on-line detection of concentration. The concentration detection system can be widely used in chemical industry, sugar, food, pharmaceutical and other industries, is a kind of concentration detecting system has the broad prospects for development. Key words: PSD, semiconductor laser diode， liquid concentration, MCU8051 目 录 - -IV 目 录 摘 要∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙I ABSTRACT∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙II 目 录∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙IV 第一章 绪论∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙1 1.1 课题设计的目的意义∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙1 1.2 国内外研究现状 ∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙1 1.2.1 位置敏感探测器(PSD)国内外发展状况∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙1 1.2.2 液体浓度测量的国内外研究现状∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙2 1.3 课题设计的主要内容∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙3 第二章 总体方案∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙4 2.1 系统。