化学需氧量测定仪的测量结果不确定度评定

本文依据JJG 975-2002《化学需氧量(COD)测定仪检定规程》对化学需氧量(COD)测定仪的A类仪器温度示值误差及A类仪器示值误差进行不确定度评定。评定方法适用于检测化学需氧量(COD)测定仪的A类仪器温度示值误差及A类仪器示值误差的不确定度评定。     

化学需氧量(COD)测定仪校准结果不确定度评定

根据JJG975—2002《化学需氧量(COD)测定仪检定规程》的检定方法,以符合规程的化学需氧量标准物质及多点温度巡检仪为标准器具,对化学需氧量(COD)测定仪的示值误差及温度示值误差校准结果分别进行了不确定度评定分析。     

化学需氧量(COD)测定仪示值误差测量不确定度评定

根据JJG 975—2002《化学需氧量(COD)测定仪检定规程》的检定方法,以符合规程的化学需氧量标准物质为标准器具,对化学需氧量(COD)测定仪的示值误差进行了不确定度评定分析。     

化学需氧量（COD）示值误差不确定度评定的分析

化学需氧量（COD）测定仪因测量原理不同分为A类、B类,两类仪器在检定规程中的COD示值误差计算方法不同,因此其不确定度评定方法也有所差异。本文对两类仪器COD示值误差的不确定度进行了详细的分析。分析结果：A类：Urel=4％（k=2）,B类：U=0．8mg／L（k=2）。     

渗透压摩尔浓度测定仪示值误差测量结果的不确定度评定

文章主要依据JJG 1089—2013《渗透压摩尔浓度测定仪》检定规程对仪器示值误差进行不确定度评定分析。     

常压机械式泥浆密度计测量不确定度评定

依据JJG1045-2017《泥浆密度计检定规程》对泥浆密度计进行检定或者校准,对示值误差测得值的不确定度进行评定。     

雷氏夹膨胀测定仪测得值的不确定度评定

本文简述了雷氏夹膨胀测定仪的工作原理,依据JJG (交通) 093-2009《雷氏夹及雷氏夹膨胀测定仪》检定规程,结合具体检定过程,对雷氏夹膨胀测定仪的检定项目建立了测量模型,分析了测得值的标准不确定度分量来源,运用不确定度评定与表示方法,给出了雷氏夹膨胀测定仪测得值不确定度评定报告。     

单相电子式电能表误差测量值的不确定度评定

本文依据JJG596-2012《电子式交流电能表》检定规程和JJG597-2005《交流电能表检定装置》检定规程对用户电能表进行检定并出示检定证书,按用户的特殊要求再依据JJF1059. 1-2012《测量不确定度评定与表示》对测得值的示值误差给出不确定度报告。     

覆膜电极溶解氧测定仪检定装置及仪器示值误差检定结果的不确定度评定

本文根据JJG 291-2008覆膜电极溶解氧测定仪检定规程中计量标准器的主要计量性能指标,评定了覆膜电极溶解氧测定仪检定装置和仪器示值误差检定结果的不确定度.     

烘干法模拟显示水分测定仪测得值的不确定度评定

烘干法水分测定仪是基于烘干原理直接对衡量样品表面分离物或微量水分进行计量分析的仪器。本文依据JJG658-2010《烘干法水分测定仪检定规程》,对模拟显示水分测定仪的测得值进行不确定度评定。     

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.     

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)。