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用蒸馏后滴定法测定磷酸二氢铵中总氮含量的测量结果的不确定度进行了分析和评定。分析和评定结果表明:磷酸二氢铵中总氮含量测量结果的合成标淮不确定度uc=0.04%,当包含因子K=2时,扩展不确定度U为0.08%。各分量中,以重复性测量和滴定管带来的不确定度分量贡献较大。 相似文献
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文章介绍了常用玻璃量器容量测量的测量不确定度分析与评定方法 ,并对 5 0ml滴定管容量测量不确定度进行了分析与评定。 相似文献
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该文作者长期从事激光干涉测量和对标准钢卷尺进行量值传递的工作,文中对标准钢卷尺测量结果不确定度的评定思路、评定方法和步骤.概率分布的处理。怎样取值和计算.尤其对标准钢卷尺任一长度的测量结果扩展不确定度,用统一表达式来表示的方法,进行了系统的论述.是一篇规范化的专业不确定度评定文章.可供有关人员工作中参考。 相似文献
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本文介绍了用于测量悬浮于水(或其他透明液体)中的不溶性颗粒物质含量的仪器浊度计的测量原理和计量单位,并依据计量检定规程(JJG880-1994)中检定示值相对误差的方法,对示值相对误差的测量结果进行不确定度评定,具体分析了各个不确定度分量的产生,并合成标准不确定度及有效自由度。评定示值相对误差测量结果的不确定度为U95rel=3.3%。 相似文献
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傅志强 《理化检验(物理分册)》2003,39(9):465-467
根据JJFl059—1999《测量不确定度评定与表示》的要求,系统地对GB/T228—2002《金属材料室温拉伸试验方法》中规定非比例延伸强度Rp0.2测量结果的不确定度进行了评定。针对金属材料力学性能检测领域的测量结果不确定度特点,选用了性能相对均匀的不锈钢板为试验材料,分析了试验过程中方法、设备、量具、人员和环境等不同因素对测试结果的影响程度。结果表明,试验条件下的非比例延伸强度Rp0.2测量结果的相对不确定度为2.55%。 相似文献
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测量不确定度是对测量结果可疑程度的一种定理表述,为减小实验误差,提高检测精确度,我们分析了饮料中菌落总数测量不确定的来源,评定了由重复性测量的分散性引起的测量不确定度.测量结果显示扩不确定度为0.0633。 相似文献
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承忠 《理化检验(物理分册)》2013,(11):756-758
5.3.3标准不确定度的B类评定
5.3.3.1评定方法
用不同于观测列的统计分析来评定的标准不确定度称为B类标准不确定度。它在不确定度评定中十分有用,是根据许多已知的信息或经验来进行评定,如所使用仪器设备的校准证书、检定证书、准确度等级、暂用的极限误差、技术说明书或有关资料提供的数据及其不确定度,还有过去的测量数据、经验等。 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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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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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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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. 相似文献