【作者】 周爱；

【导师】 苑立波；

【作者基本信息】 哈尔滨工程大学 ， 机械设计及理论， 2009， 博士

【摘要】 本课题提出了一种新型的光纤液体分析技术——蘸粘式光纤液体分析技术。该技术综合利用了物理和表面化学、光纤传感和数字图像处理等技术,通过控制光纤探头垂直进入和离开被测液体,在光纤探头和被测液体之间形成一个非对称的液桥,当液桥破裂后在光纤探头端会形成一个微小液滴。在探头相对被测液体运动的过程中,能够实现液体的浓度、折射率、表面张力和粘度等多个物理、化学参量的同时测量,并能够实时、快速地实现对液桥的形变及破裂过程的监测。蘸粘式光纤液体分析技术的结构简单,信号重复性好,可实现在线测量和监测。本文围绕蘸粘式光纤液体分析技术进行了探索性研究,建立了蘸粘式光纤液体分析技术的理论分析模型,设计并制作了蘸粘式光纤液体分析系统,并对不同溶液进行实验研究,验证了蘸粘式光纤液体分析技术的可行性。本课题主要从以下几个方面开展工作：首先,基于光纤反射式强度调制和凸透镜傍轴成像原理,分析了光纤端液滴对光线传输路径的影响,研究了蘸粘式光纤液体分析技术的输出光强调制特性,建立了理论分析模型,并仿真计算了不同折射率液体的光强调制特性曲线。其次,详细论述了蘸粘式光纤液体分析技术的传感原理,分别对液体的浓度、折射率、表面张力和粘度的各自传感特性进行了分析,并详细分析了液桥的形变和破裂过程,研究了液体各特性参数在接收光信号中的不同响应,并建立相应的分析模型。再次,基于蘸粘式光纤液体分析技术,设计并制作了蘸粘式光纤液体分析系统,其中包括光源、探测和步进电机控制电路的设计和制作,图像采集模块的设计制作,光纤探头的结构设计制作,以及基于LabVIEW虚拟仪器的数据采集及仪器控制程序的编写。利用蘸粘式光纤液体分析系统可以方便的实现对被测液体的测量分析。最后,开展了蘸粘式光纤液体分析技术的实验研究。研究了蘸粘式光纤液体分析技术对不同种类的液体的分辨能力,并对实验数据的重复性进行了分析。对同一种类不同浓度的液体(蔗糖溶液、氯化钠溶液和酒精溶液)的浓度、折射率、表面张力和粘性以及液桥的形变和破裂过程分别进行了相关实验研究。更多还原

【Abstract】 A novel fiber dipping liquid analysis technique (FDLAT) was proposed. Fiber optic technique, physical chemistry, surface chemistry and digital image processing technique were employed in FDLAT. When the fiber probe is dipped in a liquid solution and subsequently retracted, a liquid bridge was formed between fiber probe and the aqueous phase. Keep stretching the liquid bridge and a pendant droplet could be formed at end face of fiber probe after the liquid bridge broke up. FDLAT can simultaneously measure some physical and chemical parameters of liquid including concentration, refractive index, surface tension and viscosity. In addition, it can also monitor the process of deformation and breakup of liquid bridge. FDLAT has several advantages such as simple configuration, good repeatability, suitable for on-line measuring and monitoring.The function and characteristics of FDLAT was investigated both theoretically and experimentally in this thesis. The details are presented as follows:Firstly, based on fiber optic reflective intensity modulation technique and principle of plane-convex lens imaging, the influence of liquid drop on light transmission path and the light intensity characteristics of FDLAT were analyzed. The theoretical analysis model was built up and the characteristic curves of some liquids with different refractive index were simulated.Secondly, the sensing principle of FDLAT was introduced, and the sensing characteristics of concentration, refractive index, surface tension and viscosity were analyzed respectively. Moreover, the process of deformation and breakup of liquid drop was also discussed. Finally the analysis models of different parameters of tested liquid were set upThirdly, based on FDLAT the fiber dipping liquid analyzer (FDLA) was designed and fabricated, including fabrication of driving circuit of light source, detecting circuit and step motor driving circuit, image capturing module, fiber probe designing and data acquisition and processing by utilizing LabVIEW.At last, Experimental study of FDLAT. The capability to distinguish different kinds of liquid was analyzed and the repeatability of experimental data was tested. Then different solutions including sucrose-water solutions, sodium chloride-water solutions and ethanol-water solutions at different concentrations were studied experimentally.更多还原