电导率仪检定结果的不确定度分析

文章首先对电导率仪的不确定度来源进行了分析,建立了相关数学模型,对各个分量的标准不确定度进行了评定,同时也求出了合成标准不确定度及扩展不确定度,确保电导率仪测量时的准确性和溯源性。     

塑料密度测量的不确定度评定

采用D-H100型密度测定仪对聚乙烯塑料的密度测量进行了不确定度评定,分析了密度测量过程中不确定度的主要来源,并对各不确定度分量进行量化,求得合成标准不确定度和扩展不确定度分别为0.0005g/cm3和0.0010g/cm3.     

数字式标准测力仪示值测量不确定度评定

本文分析了数字式标准测力仪示值测量不确定度的来源 ,并对各项测量不确定度进行评定 ,最后给出了在 2 0 0kN、4 0 0kN、1 2 0 0kN处的扩展不确定度     

浊度仪测量值的不确定度分析及评定

本文分析了浊度仪检测结果测量不确定度的主要来源,介绍了浊度仪测量不确定度的评定步骤和方法,给出了评定结果。     

光时域反射仪检定装置测量不确定度评定

介绍了光时域反射仪检定装置的测量不确定度评定方法,此方法适用于建立计量标准的测量不确定度评定.     

医用CT剂量指数测量结果的不确定度评定

为了使医用诊断计算机断层摄影装置（CT）X射线辐射源在模体中的剂量指数测量结果的不确定度评定合理。基于用带有100mm长杆电离室的积分剂量仪测量CT剂量指数的数学模型,对其测量不确定度来源进行分析,列出了方差、灵敏系数及标准不确定度的计算公式,从而给出了CT剂量指数测量的合成标准不确定度和扩展不确定度。     

食品中亚硝酸盐测量不确定度的评定

对食晶中亚硝酸盐测量不确定度进行了评定,分析了食品中亚硝酸盐的测量原理及程序,分析了测量不确定度来源并建立数学模型,对各测量不确定度分量进行了评定,通过合成标准不确定度给出扩展不确定度.     

影像测量仪尺寸测量示值误差的不确定度分析

分析了用标准玻璃线纹尺校准影像测量仪示值误差E的标准不确定度来源,并对引入的每项不确定度分量进行了评定,最后求出扩展不确定度.     

影像探测系统的坐标测量机尺寸测量示值误差的不确定度分析

分析了用标准玻璃线纹尺校准影像探测系统的坐标测量机示值误差的标准不确定度来源,并对引入的每项不确定度分量进行了评定,最后求出扩展不确定度.     

公法线千分尺示值误差测量结果的不确定度评定

文章采用JJF1130-2005<几何量测量设备校准中的不确定度评定指南>中的方法对公法线千分尺示值误差测量结果的不确定度进行评定.给出了目标不确定度,并根据不确定度误差的来源对测量结果进行分析计算,得到合成标准不确定度.通过对目标不确定度和合成标准不确定度的大小比较来得到最终判据.     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

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.     

Analysis of the rate of propagation of the wave of change of boiling modes

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.     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

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.     

可燃气体检测报警器测量结果的不确定度评定

本文详细介绍了可燃气体检测报警器示值误差测量结果的不确定度评定方法。     

水三相点复现的不确定度评定

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)。     

心电图机电压测量示值误差测量值的不确定度评定

本文介绍了心电图机电压测量示值误差测量值的不确定度评定与表示方法。     

Estimation of potentialities of methods of summation of direct measurement errors

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.