电子式三相电能表示值误差测量不确定度评定

本文用一个实例阐述了测量不确定度的评定方法和过程。测量不确定度是误差理论的完善和发展,其分析的主体仍然是误差。从它们的定义可以看出,测量不确定度比误差更具有说明测量质量好坏的能力,测量不确定度比误差更全面更具体。     

对测量结果不确定度的分析

本文用一个实例阐述了测量不确定度的评定方法和过程。测量不确定度是误差理论的完善和发展,其分析的主体仍然是误差。从它们的定义可以看出,测量不确定度比误差更具有说明测量质量好坏的能力,测量不确定度比误差更全面更具体。     

最大允许误差与测量不确定度在产品检验中的应用

本文从一个典型的测量结果入手,论述了使用传统的最大允许误差理论对测量结果进行合格判断的过程,分析了同时使用最大允许误差和测量不确定度进行测量结果判断的理论依据,对最大允许误差和测量不确定进行了比较分析。     

激光跟踪仪多边测量的不确定度评定

激光跟踪仪多边测量是大型高端装备制造现场溯源的重要手段,正确评定其不确定度是确保制造过程量值统一、结果可靠的关键。本文提出了一种准确、快速的激光跟踪仪多边测量的不确定度评定方法。从仪器误差、环境干扰及靶球制造误差等方面分析激光跟踪仪多边测量的不确定度来源。针对多边测量的输出量为多维向量的特点,重点研究基于多维不确定度传播律(GUM法)的不确定度合成方法,同步评定目标点坐标和跟踪仪站位的不确定度。最后,介绍了点到点长度的不确定度计算方法。实验表明:GUM法评定的不确定度结果与蒙特卡洛法(MCM法)的结果相比,坐标不确定度偏差小于0.000 2 mm,相关系数偏差小于0.01,满足数值容差,且GUM法用时仅为MCM法的0.08%;点到点长度测试的En值均小于1。因此,基于GUM法评定激光跟踪仪多边测量的不确定度具有可行性及高效性,且评定结果正确、可靠。     

轴承内径测量结果不确定度的评定分析

滚动轴承内径偏差是通过与公称尺寸相同的标准件进行比较测量而获得的。根据此测量方法,分析了测量原理误差、标准件误差、温度变化及测量重复性等对滚动轴承内径测量不确定度的影响,并给出了各种不确定度的相应计算公式。     

DJ2光学经纬仪一测回水平标准偏差测量结果不确定度的分析

阐述了DJ2经纬仪一测回水平标准偏差测量结果不确定度的评定方法和过程。测量不确定度是误差理论的完善和发展,具有国际通用性。测量不确定度比误差更具有说明测量结果质量好坏的能力,表达的更确切,更具有说服力。     

对形位误差测量不确定度影响因素的探讨

通过对形位误差测量整个过程进行分析,得出影响形位误差测量结果不确定度的主要因素,并简单概括了研究形位误差测量结果不确定度的一些难点。     

轴承外径测量不确定度的评估分析

滚动轴承外径测量是在外径测试仪上,通过与公称尺寸相同的标准件进行比较测量而获得外径偏差,分析了测量原理误差、标准件误差及温度变化等对滚动轴承外径测量不确定度的影响,并给出了各种不确定度的相应计算公式。     

CO分析仪测量不确定度的评定方法及误差分析

根据监测仪器的测量原理、校准方法分析不确定度的来源,按不确定度评定原则给出测量不确定度的评定方法;根据不确定度分量值,分析误差的主要来源.     

CO分析仪测量不确定度的评定方法及误差分析

根据监测仪器的测量原理、校准方法分析不确定度的来源,按不确定度评定原则给出测量不确定度的评定方法;根据不确定度分量值,分析误差的主要来源.     

义齿的金属-陶瓷结合特性测量不确定度评定

目的 :建立义齿金属-陶瓷结合特性测定方法的不确定度评定方法。方法 :依据标准YY0621-2008测定义齿中金属-陶瓷结合特性的值,依据JF1059.1-2012确定测量不确定度的分量,合成不确定度。结果 :当样品的分离/断裂力起始强度为47 MPa时,合成不确定为1.7MPa,扩展不确定度为3.4MPa。不确定度报告表示为:τb=47 MPa,Uτb=3.4 MPa,k=2。结论:从金属基体厚度的测量、k值的读数以及万能材料试验机等方面对引起不确定性的因素进行详细讨论和计算,指出影响金属陶瓷结合特性准确性的主要因素是金属基体厚度测量误差和k值读数误差。     

干涉测距仪测量不确定度评估

本文对与干涉测距仪（IDM）测量不确定度有关的参数进行了讨论。采用一个简单、鲁棒装置测量了约12cm距离,扩展不确定性为±16．4,um,发现测量不确定度受波长测量精度制约。该设置可测量距离达56m,它也能够轻松确定测量臂和参考臂之间等光程差的点。LabVIEW程序用于条纹的计数,快速傅立叶变换（FFT）对噪声按频率进行选择性过滤。虽然本文对不确定性的测定不能代表同类测量距离的最高不确定度,但该测量方法提供了可溯源于长度单位为米的测量值。     

测量误差与测量不确定度的比较应用

文章详细介绍了测量误差和测量不确定度的基本概念以及两者之间的关系,阐述了采用测量不确定度评定测量结果的质量的必然性,旨在正确地了解掌握其实质、以便在工作中能正确地应用测量不确定度的评定与表示。     

测量误差与测量不确定度

采用对比的方法从概念、来源和分类方法等方面，比较详细地介绍了测量误差与测量不确定度的联系与区别，并阐述了两者在测量领域的作用与意义。     

分布光度计测量LED路灯光通量的不确定度评定

为了减少检测的误差,提高检测结果精确度,评定LED路灯光通量的不确定度,分析了用分布光度计法测量LED路灯光通量的影响因素,建立数学模型对测量不确定度进行评定,并计算出A类、B类不确定度,最终给出测试结果的不确定度报告。相对扩展不确定度评定结果为4.13%,置信概率P为99%。结果表明,光谱辐射计的测量误差和标准灯的不确定度所产生的测量不确定度影响因素最大。     

电子计价秤示值误差测量结果不确定度评定

本文介绍ACS-15电子计价秤示值误差测量结果不确定度的评定方法,并通过实际测量,计算出7.5kg秤量点的标准不确定度、合成标准不确定度及扩展不确定度。     

Measurement uncertainty evaluation of conicity error inspected on CMM

The cone is widely used in mechanical design for rotation, centering and fixing. Whether the conicity error can be measured and evaluated accurately will directly influence its assembly accuracy and working performance. According to the new generation geometrical product specification(GPS), the error and its measurement uncertainty should be evaluated together. The mathematical model of the minimum zone conicity error is established and an improved immune evolutionary algorithm(IIEA) is proposed to search for the conicity error. In the IIEA, initial antibodies are firstly generated by using quasi-random sequences and two kinds of affinities are calculated. Then, each antibody clone is generated and they are self-adaptively mutated so as to maintain diversity. Similar antibody is suppressed and new random antibody is generated. Because the mathematical model of conicity error is strongly nonlinear and the input quantities are not independent, it is difficult to use Guide to the expression of uncertainty in the measurement(GUM) method to evaluate measurement uncertainty. Adaptive Monte Carlo method(AMCM) is proposed to estimate measurement uncertainty in which the number of Monte Carlo trials is selected adaptively and the quality of the numerical results is directly controlled. The cone parts was machined on lathe CK6140 and measured on Miracle NC 454 Coordinate Measuring Machine(CMM). The experiment results confirm that the proposed method not only can search for the approximate solution of the minimum zone conicity error(MZCE) rapidly and precisely, but also can evaluate measurement uncertainty and give control variables with an expected numerical tolerance. The conicity errors computed by the proposed method are 20%-40% less than those computed by NC454 CMM software and the evaluation accuracy improves significantly.     

一种同位素组分差异比较的精密测量方法

In some study fields, when the enriched uranium producted form different erichment technology have the absolute same level of composition 235U, it is to be measured and compared by mass spectrometry whether there was a difference abundances of uranium isotope composition 234U. But it is hardly possible to obtain the required pairs of samples with the absolute same level of 235U abundance. If the comparison is done by means of determining a series of abundance values of the two products and fitting the curves respectively, error of the result will be enormous. In order to overcome this problem, a precise measurement method or mathematic model of the difference was deduced. The deduction of the method makes use of principle of the isotope ration to ration measurement α in mass spectrometry and the relations of 234U to 235U in the enrichment technology theory. By means of this model, through the measured α of two pairs of samples with different 235U abundance from enriched products produced by the different technology, the relative difference value at a certain level of 235U can be exactly obtained. Theoretical error of the method approximately is equal to the error of only a single α measurement, which mainly depends on the level of the instrument precision and the abundance ranges of the pairs of samples. A less than 1% of total uncertainty (relatively) was given in the practical experiments in the plant.     

Estimation of uncertainty of mean velocity of flue gas in a conduit as determined by the traverse method within the gravimetric measurement of particulate concentration

In gravimetric measurements of dust emissions from industrial technological plants, the required mean gas velocity in a conduit is often determined by Pitot traverse method. It is commonly seen as a method giving good approximate values of mean gas velocity, although the actual rate of this approximation is not considered in the analysis of measurement results. It was seen that there was a need to establish what magnitude of error might occur in practice due to the small number of measurement points and typical non-uniformity of the gas velocity profiles in conduits of rectangular cross-section. The calculations were based on the concept of treating a measurement plane as one consisting of a set of elementary planes. The elementary gas velocity profiles in these elementary planes were simulated, the mean velocity for these profiles were calculated based on point velocity values, and the measurement uncertainty of this mean velocity determined. This uncertainty results in the uncertainty of the mean velocity across the entire measurement plane. It appears that, depending on the number of measurement points and gas velocity profile non-uniformity, the value is not small and is of the order of several percent, and hence needs to be taken into account in the budget of the combined uncertainty of mean velocity, which in turn contributes to the uncertainty of gas volumetric flow rate and dust pollutant mass flow rate.