电子天平示值误差测量结果不确定度评定

本实验以电子天平为研究对象,分析了电子天平示值结果不确定度的来源[1],并详细介绍了电子天平示值误差测量结果不确定度评定的方法.     

红外吸收法测定钢中碳量的测量不确定度评定

对高频炉燃烧.红外吸收法测定钢中碳含量的测量不确定度来源进行了详细的分析,建立了合理的数学模型,概述了物质称量、标准物质认定值、测量的重复性等等各主要的不确定度分量的评定方法,对高频炉燃烧.红外吸收法测定钢中碳含量的测量不确定度进行了仔细的评定,给出了扩展不确定度,并就其对钢中碳含量测量结果的影响进行了深入的探讨.     

论测量不确定度

讨论了测量不确定度的基本概念及应用。分析了误差和不确定度两个概念的区别，探讨了不确定度及分量的评定方法。     

总悬浮颗粒物测试仪检定结果的不确定度评定

对总悬浮颗粒物测试仪检定结果的不确定度进行了评定,分析了检定过程中不确定度的主要来源,如计量标准、测量重复性、检定装置示值误差等.对各不确定度分量进行了量化,求得检定结果的相对扩展不确定度为1.8%(k=2).对检定结果不确定度评定的合理性进行了验证.     

分析方法不确定度评定的通用数学模型

在总结化学实验室常用分析方法共性的基础上,提出了常用分析方法不确定度评定的通用数学模型,介绍了各不确定度分量的计算方法.并通过适当变换,实现了该数学模型在不同分析方法(如滴定法、极谱法、原子吸收光谱法、吸光光度法等)测量结果不确定度评定中的应用.     

分析测试不确定度的评定与表示(Ⅱ)

就“不确定度”概念的来历和意义;基本术语;误差与不确定度;化学分析测量不确定度的来源;不确定度的评定;标准物质的不确定度;不确定度的评定实例等7个方面概述分析测试不确定度的评定与表示,介绍不确定度的基本知识与应用。     

分析测试不确定度的评定与表示(Ⅰ)

就“不确定度”概念的来历和意义;基本术语;误差与不确定度;化学分析测量不确定度的来源;不确定度的评定;标准物质的不确定度;不确定度的评定实例等7个方面概述分析测试不确定度的评定与表示,介绍不确定度的基本知识与应用。     

塑料中镉的测定不确定度评定

建立了用实验室内精密度和偏差的数据来评定塑料中镉的测定不确定度的方法. 通过研究不同基体和不同含量水平的样品, 考察了方法的精密度和回收率, 分别计算并合并了两者的测量不确定度. 结果表明精密度和回收率的相对不确定度分量分别为0.026和0.068, 合成不确定度为0.072, 扩展不确定度为0.14. 此评定过程为实验室评定测量不确定度提供了一种新的方法, 简单、合理, 计算结果可靠.     

分光光度法测定室内空气中甲醛含量不确定度评定

对室内空气中甲醛含量分析测试过程的误差进行了辨别.在此基础上评定了分析结果的不确定度.不确定度主要来源于样品采集、样品处理、标准溶液、标准曲线制作以及其它仪器的使用.依据不确定度评定的步骤,分析和计算得到了各分量不确定度和合成不确定度.     

超高效液相色谱法测定化妆品中孕激素的不确定度

采用分层建模方法建立了超高效液相色谱法测定化妆品中黄体酮结果不确定度评定的数学模型,对测量过程中的不确定度来源进行逐层分析和合成,运用最小二乘法对外标曲线拟合的不确定度进行了评定.超高效液相色谱法测定化妆品中孕激素含量的相对合成标准不确定度为0.022,相对扩展不确定度为0.044.该评定对采用外标法定量的高效液相色谱、气相色谱等测定结果的不确定度评定具有参考作用.     

Estimation of the uncertainty of mass measurements from in-house calibrated analytical balances

The uncertainty evaluation of mass measurements when using “in-house” calibrated analytical balances is revisited according to the Guide to the expression of Uncertainty Measurement (GUM). The calibration of analytical balances is discussed according to the guidelines of several bodies such as ASTM, UKAS and DKD/PTB. The remainder components of uncertainty can be estimated from the balance data sheet specifications.     

分析实验数据处理中的测量不确定度

在现行的分析标准中,大多未对测量不确定度提出相应的要求．本文通过对测量不确定度概念的探讨及对几种化验数据的测量不确定度分析,对检测数据出具时的规范化、标准化有重要意义．     

Newton's Laws, Planck's Principle, and Metrology in Chemistry

This quasi-serious joke is an attempt to interpret human behaviour in terms of Newton's Laws of motion and Planck's Principle, with reference to the interaction of chemistry with “classical” metrology. Papers published in this section do not necessarily reflect the opinion of the Editors, the Editorial Board and the Publisher.     

原子吸收法测定矿石中钴的不确定度评定

利用原子吸收光谱法评定了矿石中钴测定的不确定度,为质量控制提供有效、可靠的测量数据。结果表明,测量结果的不确定度由钴的质量浓度C0、称样质量m0、试液定容体积V等引入的不确定度分量组成,而主要分量是钴的质量浓度。     

冷原子荧光法测定蔬菜中痕量汞的不确定度评定

对冷原子荧光法测定蔬菜中痕量汞的不确定度进行了评定。不确定度来源主要为配制标准工作溶液引入的不确定度,称取样品质量引入的不确定度,样品消化引入的不确定度,定容体积引入的不确定度,重复测定引入的不确定度。当蔬菜中汞含量为5.2μg/kg时,测量结果的扩展不确定度为0.50μg/kg。     

On the generality of a cosmological speculation based on Heisenberg's principle

In a previous work [Hernández-Bermejo, B. (1996) Heisenberg's principle: A cosmological speculation, Speculations in Science and Technology, 19, 253], it was speculated that the lack of homogeneity of the large-scale structure of the universe may be due to quantum fluctuations of space in the early universe. This was argued for a Friedmann-type universe for which both the curvature and the cosmological constant were zero. Here it is shown that the same considerations are valid for arbitrary values of the curvature and .     

The uncertainty of atomic mass fractions in a molecule

The mass fraction of a certain atom species in a molecule is needed for the calculation of the result of some chemical analyses. Common examples are gravimetric determinations (e.g., the sulfur concentration in a sample that can be obtained from the mass of precipitated barium sulfate). A similar problem is encountered when a reference solution of an ion is prepared by dissolution of a salt. This paper presents how the uncertainty of the mass fraction is calculated from the uncertainties of the atomic weights as published by IUPAC. The value is needed for the determination of the combined standard uncertainty of the analysis. Some calculated examples illustrate the mathematical considerations presented in the paper.     

How to revise the GUM?

The announcement of a revision of the Guide to the expression of uncertainty in measurement has renewed the debate about the topic of measurement uncertainty. In this paper the author, chairman of Working Group 1 of the Joint Committee for Guides in Metrology, replies to the theses given in two recent papers by Semion Rabinovich. His opinions are personal, and are not necessarily shared by the JCGM/WG1. They are to be intended as a further contribution to the present discussion. Papers published in this section do not necessarily reflect the opinion of the Editors, the Editorial Board and the Publisher.     

Uncertainty of the result of TOC determination in water samples

It is becoming increasingly important to have a reliable and rapid technique for determining total organic carbon (TOC) in wastewater as procedures for wastewater purification could be better applied by knowing the amount of TOC in the wastewater. We describe here an evaluation of the uncertainties associated with TOC determinations in wastewater. TOC was determined by combustion and an infrared (IR) detection method, as described in the standard procedures of the International Organization for Standardization (1999; no. 8245). The major sources of uncertainty in the measurements were identified as being contributions from the linear least square calibration, repeatability, recovery and stability of the sample (storage conditions). A 10% relative expanded uncertainty of TOC measurement in the range of 0.2 to 500 mg L⁻¹ TOC was calculated, which also includes the uncertainty due to sampling.