共查询到20条相似文献,搜索用时 62 毫秒
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本文首先介绍了不确定度的概念以及不确定度的来源,然后针对示波器带宽的校准,详细分析了示波器带宽校准的不确定度来源,并以校准安捷伦54642D为例,详细介绍了示波器带宽的测量不确定度评定方法。 相似文献
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本文介绍了模拟和数字示波器时基电路的原理,说明了时间因数检定方法的异同,分析了影响测量结果不确定度的因素,并对测量结果的不确定度进行了评定和比较。 相似文献
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介绍了用阶跃响应法评价数字存储示波器上升时间的测量不确定度分析与评定过程。讨论了主要的不确定度来源,包括信号源上升时间及其误差、示波器时基误差、示波器幅度测量误差、上升时间区间端点处波形曲线随变化率的影响,以及测量重复性等,给出了不确定度模型,以及减小不确定度的主要措施,并结合实例,给出了上升时间的不确定度评定结果。 相似文献
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李艳 《现代测量与实验室管理》2011,19(2):24-25
根据数字存储示波器校准规范和测量不确定度评定与表示规范,用9500B示波器校准仪对数字示波器幅度测量相对误差测量的测量方法进行分析,并对测量不确定度进行了评定和分析。 相似文献
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文章依据JJG262-1996模拟示波器检定规程,用FLUKE-5820A示波器校准仪直接对示波器的垂直偏转系数误差与水平偏转系数误差进行了测量.根据测量方法,由实测数据,对测量时的不确定度进行了分析及评定. 相似文献
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文章简单介绍使用电平振荡器、选频电平表、标准衰减器、示波器校准仪对钢轨探伤仪检定仪检定的测量结果的不确定度评定。 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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