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为简化实际操作中金属材料拉伸试验测量不确定度的评定程序,确定合理的不确定度评定方法,保证测量系统不确定度真实反应测量系统的测量能力和系统的测量稳定性.本文根据JJF 1059.2-2012的要求,以58 SiMn圆形棒材抗拉强度测量系统为实例,对其进行了不确定度评定,同时分析了该系统各不确定度分项的来源及对评定结果的影响.提出了评定方法的选择、测量系统要求、对各不确定度分量的取舍等观点,可作为对进行拉伸试验不确定度的评定及其他测试系统不确定度评定的参考. 相似文献
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在实际校准工作中,发现测量不确定度的评定繁杂,难于操作。我在压力表校准中,总结出一种简易的校准评定方法和同行们共同探讨。例:客户提供了一块准确度等级为0.4级、测量范围为(0~1.6)MPa的精密压力表,要求对1.2MPa的示值进行校准,并给出校准结果和测量不确定度,同时签 相似文献
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利用评定与表示测量不确定度的通用规则和流程,按照GB/T15481-2000对检测实验室的要求,本文以锚具洛氏硬度为例进行了测量不确定度的评定与表示,通过实例评定,分析并确定了锚具洛氏硬度测量不确定度产生的主要来源,了解了测量不确定度的评定流程,掌握了测量不确定度的评定方法,评定结果是科学的、合理的. 相似文献
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范华 《现代测量与实验室管理》2014,(6):30-32
本文以测量误差与测量不确定度的定义解析,了解两者的区别,在概念上加深对测量不确定度的理解;通过介绍测量不确定度A类和B类评定方法的异同点,使检测人员初步认知测量不确定度的评定方法,为今后开展测量不确定度的评定工作打下基础。 相似文献
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利用测量不确定度的评定方法对计量器具进行评定,可以确定其是否满足预期的使用要求。文章通过对选定的一块普通压力表进行测量不确定度评定的应用实例,表明了测量不确定度的具体应用方法及测量结果的不确定度。 相似文献
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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. 相似文献
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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. 相似文献
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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)。 相似文献
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Liebert A Wabnitz H Grosenick D Möller M Macdonald R Rinneberg H 《Applied optics》2003,42(28):5785-5792
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. 相似文献
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