钢丝测力仪示值误差测量结果的不确定度评定

本文根据国家计量技术规范JJF1059-1999<测量不确定度评定与表示>、国家计量检定规程JJG911-1996<钢丝测力仪>并结合工作中的实际经验,对钢丝测力仪示值误差测量结果不确定度进行评定.     

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。     

电导率仪检定或校准结果的测量不确定度评定

依据JJG376-2007《电导率仪检定规程》,电导率仪主要测量项目是电子单元引用误差和仪器重复性两大项。因此评定电导率仪的测量不确定度也就是评定其电子单元引用误差和仪器重复性测量的不确定度。     

电导率仪示值误差测量结果的不确定度评定

本文依据JJG376-2007《电导率仪检定规程》,对电导率仪仪器示值误差测量结果的不确定度进行了评定,给出不确定报告。     

电导率仪引用误差及盲样检测值的测量不确定度评定

本文依据JJG376-2007《电导率仪》检定规程,对检定电导率仪"仪器引用误差"项目的测量不确定度以及用经检定合格的仪器测量盲样的测量不确定度进行了分析评定。     

机械天平示值测量结果不确定度评定

本文结合实际检定工作,参照国家计量技术规范JJF1059-1999<测量不确定度的评定与表示>,依据JJG98-2006<机械天平>检定规程,对机械天平示值误差测量结果的不确定度进行了评定.     

电导率仪示值误差测量不确定度评定

本文根据JJG376—2007《电导率仪检定规程》和JJF1059—1999《测量不确定度评定与表示》分别对电导率仪的电子单元部分和仪器部分的示值误差的测量结果进行不确定度评定。     

电导率仪引用误差测量的不确定度评定

本文介绍了用检定规程对0.2级电导率仪引用误差测量的不确定度评定方法。     

圆柱度测量仪示值不确定度评定

针对JJG429-2000检定规程中存在的问题,根据测量不确定度与误差的关系,提出在高精度圆柱度仪检定中应以圆柱度测量不确定度评定的方法给出示值不确定度,从而取代规程中圆柱度仪示值误差检定,并以TR290圆柱度仪为例作了介绍.     

电子天平示值误差测量结果的不确定度评定

本文就本所的F2等级砝码标准装置,结合JJG1036-2008<电子天平检定规程>要求,对电子天平示值误差测量结果的不确定度进行评定.     

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.     

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.     

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.     

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)。