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我们设计了一种简单的光栅结构,不用透镜而只用粗光栅(如每毫米三条线的光栅)就可直接得到莫尔条纹,还可以克服条纹弯曲的缺点。甚至在弧形光栅的情况下边,可以产生直线平行的质量很好的莫尔条纹。结构如图所示,将动光栅和定光栅的线条以及线光源都装成互相平行(实际上稍有一些 相似文献
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一、数显装置的工作原理数显装置由光栅传感器和光栅数显表组成 ,基本组成部分如图 1。光栅传感器的结构如图 2。光源 1发出的光经聚光镜 2形成平行光 ,通过主光栅 3和副光栅 4产生明暗相间的莫尔条纹 ,当主、副光栅发生相对位移时 ,莫尔条纹发生相应变化 ,光电接收器 5 (一般为硅光电池或光电三极管 )接收莫尔条纹信号 ,并将光信号转换为电信号 ,此电信号随莫尔条纹的变化而变化 ,其变化的曲线近似为正弦波 ,经滤波、放大、整形、计数、送入计算机处理 ,在数显表上给出结果 ,并可打印、记录。数显装置采用的是开启式光栅传感器 ,在图 2中 :… 相似文献
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无衍射光莫尔条纹空间直线度测量的原理与实验 总被引:6,自引:0,他引:6
提出用无衍射光和莫尔条纹进行空间直线度测量的技术。无衍射光用作直线基准并照射在一环光栅上,由于无衍射光斑也是一系列环状条纹,因此光栅上将发生莫尔条纹,光栅固定在移动物体上,若运动轨迹偏离无衍射光的中心线,莫尔环就将发生偏离,莫尔环的偏离量数倍于光栅的偏离量,由此产生一放大的二维直线度信号,图像处理技术用于计算机莫尔环的中心,理论和实验表明,该方法具有高灵敏度和抗激光漂移的优点。 相似文献
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用虚光栅移相莫尔条纹法测量光学元件的角度偏差 总被引:2,自引:0,他引:2
引入一种处理静态干涉图的新方法———虚光栅移相莫尔条纹法,详细介绍了此方法的原理。它是一种基于虚光栅技术、移相技术和莫尔技术的载频图像处理方法,用这种方法处理一幅加有载频的干涉图时,可以实现干涉条纹移相的效果,且没有移相误差。以玻璃立方体楔角为例,介绍了虚光栅移相莫尔条纹法在光学元件的角度偏差测试方面的应用,给出了实验结果,并与ZYGO的测试结果进行比对,结果吻合,从而证实了这种方法的可行性。测量精度可达到0.1″,因此可应用于对角规精度的标定。 相似文献
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本文讨论了理想环形莫尔条纹获取的必要条件,推导出形成环形莫尔条纹的圆光栅刻线偏心量的理论计算公式,并提出了一种圆光栅刻划偏心量的快速调试方法。 相似文献
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本文应用信息理论建立莫尔-富氏光场的数学模型,讨论误差对莫尔信号的调制,以期作为规定计量圆光栅质量指标的依据。所得结论对计量长光栅也同样适用。 相似文献
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A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling. 相似文献
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Liebert A Wabnitz H Grosenick D Möller M Macdonald R Rinneberg H 《Applied optics》2003,42(28):5785-5792
A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue. 相似文献
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Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995. 相似文献
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由于空压机进气侧轴承箱蜗壳温度探头密封效果不好,使空压机及其后续管道受到油污染。后将温度探头的O形圈密封改为骨架油封,杜绝了轴承箱漏油问题。文章简介空压机的结构和技术参数,详细介绍了骨架油封的制作和优点。 相似文献
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M. M. Gadenin 《Inorganic Materials》2013,49(15):1352-1356
It is shown that conditions of attainment of marginal states in the material of structural components are formulated on the basis of analysis of force and deformation criteria of formation and development of destruction. The parameters of these criteria are data on types of structural materials, standard and special characteristics of their mechanical properties, structural forms of considered elements of the equipment, and their operating stress loading. In this case, the construction of a system of state equations for describing interrelation of current damage, external actions, and responses to them is based on the concept of calculating variations in properties of materials at all stages of the design life cycle. 相似文献
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V. T. Kornienko 《Strength of Materials》1991,23(7):760-765
The article suggests a method of evaluating the microstructural inhomogeneity of deformation of metals by modeling. The method includes the measurement of deformations of metal according to meshes of a dividing grid with small base and the calculation of the distribution parameters of microdeformations in model representation. It is shown that the modeling method makes it possible objectively to evaluate the microinhomogeneity of deformation of metals independently of the chosen mesh size of the dividing grid. New structural characteristics are introduced: the base and wave of variation expressing the degree of crumbling or amalgamation of metal grains by inhomogeneity of deformation.Translated from Problemy Prochnosti, No. 7, pp. 40–44, July, 1991. 相似文献
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An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a
rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate
agreement is demonstrated between the derived relations and experimental data. 相似文献
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水三相点是开尔文热力学温度的唯一基准点,也是ITS-90国际温标重要的定义固定点。因此,水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来,中国计量科学研究院研制出一系列高质量的水三相点容器,加强了水三相点的研究,为不确定度的分析提供了更为可靠的实验依据。同时,不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此,根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明,其扩展不确定度为0.16mK(k=2.69,P=0.99)。 相似文献