【作者】 杨娟；

【导师】 陆建； 卞保民；

【作者基本信息】 南京理工大学 ， 测试计量技术及仪器， 2008， 博士

【摘要】 悬浮颗粒光散射计数法因测量速度快、精度高、重复性好及适用于在线测量等优点而在洁净领域得到了广泛应用。但由于计数法颗粒质量测量的理论模型没有严格建立在测量统计学基础上,至今未能揭示不规则颗粒的分形基本特征,这也导致质量反演计算模型的不完善。针对这个问题,本文探索将信息概念和信息论方法引入悬浮颗粒计数法质量测量领域,研究颗粒不规则形貌特征决定的分形测度特性,建立用计数信号相对幅度计算同质量颗粒子集等效质量的理论模型。论文首先建立了颗粒质量子集概念,并且将其加以推广,应用“等效质量”代替现有测量模型中的“等效粒径”作为不规则颗粒基本参数。然后,根据测量的统计性,将信息概念和信息论方法应用于分析物理测量过程,探讨测量信息论中信息概念的内涵,提出信息是“测量统计的形式结构以及该结构精细程度的度量”的新观点。同时,应用信息概念和信息论方法研究悬浮颗粒数的质量分布结构特征、计数法测量颗粒过程中信号数的幅度分布结构特征,提出与计数信号幅度档对应信号数“等效质量”的概念,建立了计数法颗粒质量测量的基本原理。将新的测量原理与统计学理论再结合,建立了密度相同条件下不规则颗粒质量子集等效体积的分形测度模型,从理论上给出了颗粒测量领域中表现出来的颗粒群分形特征成因。论文以光散射计数法悬浮颗粒质量传感器为应用实例,结合传感器光敏区光强不均匀性,研究颗粒散射光信号幅度档等效颗粒质量一般计算公式(?),发现颗粒光散射等效截面分形维数α不仅包含颗粒群质量分布信息,还包含了光敏区中颗粒数空间分布信息。理论上证明了,该模型能够适用于0-5mg浓度条件下的信号计数法颗粒测量领域中。从而解决了多通道计数法颗粒质量测量的基本理论问题,指导着粒子计数器向着高性能、高水平的方向发展。更多还原

【Abstract】 Aerosol scattering counting method has been widely used in the cleaning field due to fast, high precision, good repetition and suitable for on-line measurement. However, due to the theory model of aerosol mass measurement by using counting method hasn’t been strictly founded on the measure statistics, the fractal character of irregular particles can’t be opened out up to now, which leads to the inverse calculation model of mass is incomplete. Aiming at this problem, information idea and theory will be introduced to the field of aerosol mass measurement by using counting method in this paper. Then, the fractal measurement characteristic decided by the irregular shape character of aerosol will be studied. At the same time, the theory model also will be established which uses the counting signal relative amplitudes to calculate the equivalent mass of aerosol mass subset.The conception of mass subset is proposed for aerosol firstly in this paper. And it has been extended to the equivalent mass, which is used to substitute the equivalent diameter and as the basic parameter of irregular particles. According to statistical character of measurement, information idea and theory are used to analyze the physical measuring process. And then, the connotations of information concept in measuring information theory are discussed. Meanwhile, the new viewpoint that information is the measurement of structure and the detailed degree of structure description for statistical expressional form is proposed. Besides, information idea and theory are also used to research the structure character of aerosols’ mass and amplitude distributions of signal counting in the process of aerosol measurement. In further, the conception of the equivalent mass corresponding to counting signals channel is also proposed. Based on these, the essential principle is founded for aerosol mass measurement by using counting method. As a matter of fact, combining this new measuring principle with statistics, the fractal measurement model of aerosol’s equivalent volume for counting signal is established under the condition of the same density. In conclusion, this model gives the cause of formation of fractal character in the field of aerosol mass measurement.Afterward, the aerosol mass measurement sensor with light scattering counting method is used as an example, and combining with the nonuniformity of light intensity in sensitive volumes, the general function (?) of average mass and characteristicparameter of counting channels is obtained. In fact, the indexαis the fractal dimension of equivalent scattering section which includes the information of the aerosols’ mass and space distributions in the sensitive volumes. Finally, it can be proved that the model can be used in the field of aerosol measurement by using signal counting method with the sampled concentration is limited from 0 to 5 milligram. In a word, the elemental measure theory of aerosol mass measurement is resolved by using multi-channel counting method. Especially, this work will guide the particle counter’s development toward the high level and performance.更多还原