电子计价秤示值误差测量结果不确定度分析

本文以电子计价秤为研究对象,结合实际检定工作,介绍了电子天平示值结果不确定度的来源,运用不确定度评定与表示的方法,分析了电子计价秤示值误差测量的不确定度。     

电子计价秤比对测量值的不确定度评定

电子计价秤比对测量值的不确定度评定概述、测量方法、测量模型、标准不确定度评定、标准不确定度分量、合成标准不确定度的评定、扩展标准不确定度的评定。     

电子汽车衡示值误差测量结果不确定度评定

本文结合实际检测工作 ,根据JJF1 0 59- 1 999《测量不确定度评定与表示》规范要求 ,对电子汽车衡示值误差测量结果不确定度进行了分析与评定。其结果对电子汽车衡的检定与校准工作具有一定的参考价值。     

电子汽车衡示值误差测量结果的不确定度分析

文章依据JJF1059-1999《测量不确定度评定与表示》对非自动秤检定装置中的电子汽车衡示值误差测量结果不确定度进行分析、讨论,利用实例提出了对电子汽车衡测量结果不确定度评定的方法,并对不确定度评定的步骤进行了详细的说明。     

气相色谱仪ECD检测器检测限测量结果不确定度的评定

文章依据JJF 1059—1999《测量不确定度评定与表示》,对气相色谱仪电子捕获检测器(ECD)的主要技术指标检测限的测量结果进行了不确定度评定。分析了各不确定度分量,建立了评定检测限测量结果不确定度的数学模型,并计算了其测量结果的扩展不确定度。     

电导率仪引用误差的测量不确定度评定

依据JJF 1059-1999《测量不确定度评定与表示》及JJG376-2007《电导率仪》检定规程评定了电导率仪电子单元引用误差及仪器引用误差测量结果的不确定度。建立了评定电子单元引用误差及仪器引用误差测量结果不确定度的数学模型,分析了各不确定度分量,并计算了合成不确定度和测量结果的扩展不确定度。     

石英电子秒表校准方法及测量结果的不确定度评定

本文简要介绍了石英电子秒表校准方法,对石英电子秒表时间校准时测量结果的不确定度进行分析,找出影响测量不确定度的因素,给出测量结果的不确定度,使它符合国家计量技术规范JJF1059《测量不确定度评定与表示》的要求。     

石英电子秒表校准方法及测量结果的不确定度评定

本文简要介绍了石英电子秒表校准方法,对石英电子秒表时间校准时测量结果的不确定度进行分析,找出影响测量不确定度的因素,给出测量结果的不确定度,使它符合国家计量技术规范JJF1059《测量不确定度评定与表示》的要求.     

电子专用测试设备测量不确定度来源分析

本文基于电子专用测试设备测量结果不确定度的评定需求,结合电子专用测试设备的组成特点,从供电、隔离度、平坦度、衰减、相位、噪声、通用设备、环境八个主要方面分析了测量不确定度来源,用于测量结果不确定度的评定.     

电子汽车衡测量结果不确定度评定

本文介绍了电子汽车衡不确定度的来源、测量结果评定的方法及不确定度的报告与表示,通过分析计算对测量结果有了一个定量的描述。     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

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.     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

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.     

Estimation of potentialities of methods of summation of direct measurement errors

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.     

空压机轴承箱蜗壳温度探头油封改造

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。     

Characteristics of mechanical properties of materials in studies of conditions of attainment of marginal states

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.     

Determination of parameters of microstructural inhomogeneity of deformation of metals by the method of modeling

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.     

Analysis of the rate of propagation of the wave of change of boiling modes

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.     

水三相点复现的不确定度评定

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)。