测量不确定度实际应用讲座（二）：测量不确定度的评定方法

本文依据BIPM，IEC，IFCC，ISO，IUPAC，IUPAP，OIML七个国际组织于1993年制定并于1995年修订的“测量不确定度表达指南（GuidetotheExpressionofUncertaintyinMeasarement）”，对测量不确定度的计算和表达方法作一介绍。1．常用术语与定义测量不确定度（uncertaintyofmeasarement）：与测量结果相关联的参数，表征合理地赋予被测量值的分散性。标准不确定度（standarduncertainty）：用标准偏差估计值表示的不确定度。A类标准不确定度（typeAstandarduncertainty）或标准不确定度的A类计算方法（typeAevaluationofstandard…     

认真对待“测量不确定度表示指南ISO1993（E）”中的问题

编者按：今年本刊在“计量培训”栏目中举办的《测量不确定度实际应用讲座》，是以国际计量局（BIPM）等七个国际组织联合制定的“测量不确定度表述指南（GUM）”为依据的。本期我们在“计量工作研究”栏目中刊登的钱钟泰等同，志撰写的文章，则是对GUM提出了挑战。作为学术讨论，应允许多家之言，其目的是为了活跃学术研究气氛，充分反映对测量不确定度理解方面的不同观点和建议。一、“国际通用计量学基本术语”（第二版）及“测量不确定度表示指南ISO1993（E）”两个文件之间的矛盾BIPM等七个国际组织于1993年同时制定了“国际通…     

色散型红外分光光度计的测量结果不确定度分析

色散型红外分光光度计是国家规定的强检项目之一。在其作为国家实验室认可项目时，须有测量不确定度分析报告。这个报告的表述，必须符合国际标准化组织颁布的“测量不确定度表示导则ISO1993（E）”的要求。根据这个要求，本文采用相对法求出线性回归方程，然后对方程的有关项进行不确定度分析，从而得到被测量的不确定度。这种方法对理化类的许多认可项目亦有参考价值。     

"测量不确定度"应用研究初探

一、前言测量不确定度是建立在现代误差理论基础上的新概念,其理论体系是对经典误差理论的充实和完善。在全球经济和市场激烈竞争的今天,测量不确定度的研究和统一是进行国际贸易和技术交流所必不可少的,这一观点已逐渐被各层次的计量工作者所认同。因此,对国际公认的权威性文件——《测量不确定度表示导则则501993（）的研究、推广、采用也受到了各国计量工作者的高度重视。为适应科研、生产发展形势的需要,我们于1996年以科研课题的形式开展对“测量不确定度”的应用研究,探讨和摸索在工业企业的测量领域中如何采用实施旧01993（E…     

日常检测中测量结果不确定度的评定

当前国际上所承认并在执行中的ＧＵＭ（测量不确定度表述导则 ,１９９５修正再版）以及据以制定和原则上等同采用的ＪＪＦ１０５９—１９９９《测量不确定度评定与表示》在有些人认为 :所规定的方法过分迁就基标准研究及其国际比对工作的需要 ,忽视了“一般测量”与“基标准研究”间的本质差异 ,使得它在“一般测量”领域是不可执行的 ,从而无法在广泛的领域内充当统一测量准确度评估方法的基础。ＪＪＦ１０５９—１９９９所规定的规则 ,不仅适用于建立国家计量基准、计量标准及其国际比对 ,而且也适用于生产过程中的检验和测试等大量日常的…     

轮廓仪测量系统的不确定度

本ＩＳＯ１９９３（Ｅ）《测量不确定度表示导则》,分析了５Ｐ－１轮廓仪微机测量系统量传粗糙度参数Ｒａ、Ｒｙ和Ｒｚ时朱确定度及自由度,同时确定其合成标准不确定度和扩展（总）不确定度,并地系统的性和稳定性进行了考核,以及对不确定度进行了严格的验证。     

Monte-Carlo法在测量不确定度评定中的应用

1引言 工业生产、科学实验、发明创造等都离不开各种测量手段，对参量测量的准确性是对产品质量和科技成果可信度的直接评价，间接地也影响到科技和经济的发展。对于测量结果的准确性，过去长期以来一直用测量值相对于被测量真值的误差来表示，但是由于被测量的真值是一个未知数，因此使过去的表示法产生了定量的困难。国际上早在六十年代就提出了用“不确定度”来定量表示测量结果可信程度的建议，也就是说，在当前认识条件和某个置信水平下定量给出被测量值在某一范围之内。此原则澄清了一系列模糊概念，被国际计量委员会（CIPM）和国际计量局（BIPM）所肯定，并向各国推荐，得到了一致同意。国际标准化组织（ISO）还为此提出了《测量不确定度表示导则》。这一概念上的革新将使测量技术对科技和工业生产起到更实际的积极作用。     

数字指示秤的示值误差测量结果的不确定度评定与表示

文章介绍了“数字指示秤示值误差测量结果的不确定度评定”的规范化步骤与方法，并给出了测量不确定度的报告与表示。     

热能表示值误差测量不确定度评定

文章根据 JJF1059—1999《测量不确定度评定与表示》的要求,依据 JJG225—2001《热能表检定规程》,对热能表示值误差的测量不确定度进行分析。通过 A、B 两类测量不确定度的具体分析与计算,评定了热能表示值相对误差测量不确定度的具体实例。     

关于测量不确定度的分类问题

目前，我国计量测试领域正根据国际标准化组织（ISO）、国际计量局（BIPM）等7个国际组织联合发布的“测量不确定度表述指南（1993）”来统一测量不确定度的表述，以与国际接轨。但是在学习和宣传中，本文作者感到有若干问题值得商榷，以便正确理解和应用。关于测量不确定度的分类问题便是其一，这里想进一步讨论。一种代表性的观点，如刊登在《中国计量》1996年第9期中的一篇文章中阐述的，是将测量不确定度的分类归纳表示如下图。首先，A类或B类标准不确定度（ShalwhUncef1Lllnty）是对不确定度分量的评定。通常一项测量有若干个（如…     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Friction Stir Processing Strategies for Uniform Distribution of Reinforcement in a Surface Composite

Friction stir processing (FSP) is an important technique for preparing surface composites. Fabricating defect-free surface composites with uniform particle distribution by FSP is a challenging task. In this study, silicon carbide particles reinforced AA5083 alloy surface composites was fabricated using different FSP strategies including variation in process parameters, dual-tool processing and tool offset overlapping. Material flow of the processed material with reinforcement particles demonstrated that the distribution of particles was influenced by the stirring action of the probe as well as the extrusion of the plasticized material due to the movement of the tool. Process parameters, particularly rotational speed, showed a dominant influence on the distribution of silicon carbide particles.