聚磷酸铵中有效磷含量测定结果的不确定度评定

本文用ISO／IEC17025中规定的方法对聚磷酸铵中有效磷含量测定结果的不确定度进行了评估,考虑了引起不确定度的主要原因,推出了计算不确定度的数学模型及传播系数,并计算出了各种不确定度分量,同时以具体实例说明了各种计算参数的确定和计算过程．     

药用聚丙烯密度测量的不确定度评定

目的:评估药用聚丙烯瓶密度测定的不确定度,以控制药品包装材料的质量。方法:通过建立数学模型,分析称量、温度、容积密度等因素对密度测量不确定度的贡献,计算各不确定度分量,对药用聚丙烯瓶密度的不确定度进行评估。结果:给出合成不确定度和扩展不确定度,不确定度主要来源于样品质量的称量。结论:建立的方法可用于药用聚丙烯瓶密度测定的不确定度评价。     

熔融制样-波长色散X射线荧光光谱法测定铁矿石中二氧化硅含量测量不确定度评定

本研究采用熔片制样-波长色散X射线荧光光谱法测定铁矿石中二氧化硅含量,并对其不确定度进行了评定。建立了不确定度评估的数学模型,对不确定度来源进行了分析,分别计算出不确定度分量并合成不确定度,最终确定了分析结果的置信区间。评估结果表明,校准样品及工作曲线的不确定度对测量不确定度的影响最大。     

高效液相色谱法测定维生素B_6片含量均匀度的不确定度评定

通过对高效液相色谱法测定维生素B_6片含量均匀度的分析,建立计算高效液相色谱法测定含量均匀度的数学模型,找出影响不确定度的因素,并对各个不确定度分量进行评估,由此计算合成不确定度,最终给出测量结果的扩展不确定度和置信水平。     

工作测振仪频率响应幅值示值误差的不确定度评定

本文主要介绍采用振动比较法进行工作测振仪频率响应幅值校准的不确定度评估,从数学模型的建立、标准不确定度分量的分析与计算,给出了工作测振仪通频带频率响应加速度幅值示值误差不确定度评估的结果,为振动计量领域应用最为广泛的振动比较法校准提供了不确定度评估的参考范例。     

高效液相色谱法测定糖果中苯甲酸含量的测量不确定度评定

依据JJF 1059. 1《测量不确定度评定与表示》的规定,对采用高效液相色谱法检测糖果中苯甲酸含量的不确定度进行分析,分析并找出影响该项目检测结果的不确定度的各种因素,并计算合成不确定度和扩展不确定度,为该项检测方法的研究与检验检测结果的评估提供理论依据。通过不确定度评估结果显示,对该项目检验检测结果的合成不确定度影响较大的分量是回收率分量、测量结果的重复性分量和标准曲线拟合分量。     

微晶蜡含油量不确定性评估

分析了微晶蜡含油量测定过程中影响检测结果的不确定度因素并进行了评估。通过计算重复性、残油质量、样品质量、溶剂体积、蒸发溶剂体积等因素带来的不确定度,得到了微晶蜡含油量测定结果的合成不确定度。实验结果表明,微晶蜡含油量测定不确定度主要影响因素为重复性,其次是溶剂体积和残油质量带来的不确定度。通过对不确定度进行评估,有利于提高检测结果可靠性,可以为准确测定微晶蜡含油量提供理论依据。     

基于多项式混沌理论的不确定度评定与分析

针对基于ISO GUM提供的测量不确定度评估方法所存在的局限,提出了采用多项式混沌方法进行测量结果不确定度评估的新方法。分析了GUM测量不确定度评估方法所隐含的假设条件,给出了多项式混沌方法的测量不确定度评估原理。通过GUM与多项式混沌方法扩展不确定度包含因子估计误差的数值计算表明,当随机变量的PDF不满足高斯分布时,多项式混沌估计方法所获得的扩展不确定度更能反映实际情况。     

静态扭矩测量仪的测量不确定度评定

本文对静态扭矩测量仪的测量不确定度进行了分析和评估,并根据JJG995-2005静态扭矩测量仪检定规程的检定项目及其技术指标,列出其测量不确定度的计算公式。同时提供一评估和计算实例,为该种计量器具的校准工作提供了不确定度方面的参考。     

企业核算碳排放量不确定度评估

企业是我国碳交易市场的主体交易者,由于在碳核查中大量使用缺省数据,造成排放量数据可信度下降,并且企业排放量数据的不确定度未曾评估.在对3个行业的6家企业进行了碳排放量实测后,使用蒙特卡罗法(MCM)不确定度评估方法对采用缺省值、实测值及两者组合计算得到的碳排放量数据进行不确定度分析研究.6家企业的平均计算结果表明,与全...     

用锌凝固点和水沸点检定二等标准铂电阻温度计的扩展不确定度评定

按时规范,ＪＪＦ１０５９－１９９９,对二等标准铂电阻温度计在锌凝固点及水沸点检定的不确定度进行了评定,通过建立测量数学模型确定各标准各不确定度分量,并按不确定度传播公式给出固定点间各温度点的扩展不确定度及包含因子。     

导爆索内径尺寸测量不确定度的评定及数据处理模型

针对在导爆索内径尺寸测量中存在由误差引起的被测量真实值难以确定、测量结果存在不确定性这一问题,该文重点从峰值时间和不确定度两个角度出发,改进峰值时间的提取方法,通过分析测量方法,采用不确定度A类和B类评价对相应的参数进行评定,建立数据处理模型,并采用曲线拟合的最小二乘法对结果进行拟合,使结果直观化。实验结果表明:经过该模型处理后的测量结果具有较高的准确度。     

Uncertainty evaluation for the spectroradiometric measurement of the averaged light-emitting diode intensity

An uncertainty evaluation is presented for the spectroradiometric measurement of the averaged LED intensity (ALI), which is a standardized photometric quantity of LEDs introduced by the Commission Internationale de l'Eclairage. Using a spectral irradiance standard lamp as a calibration source for the spectroradiometer, 12 uncertainty components are sorted out and their propagation formulated with correlations between the components taken into account. The procedure of uncertainty evaluation is demonstrated for four LED samples of different colors; red, green, blue, and white. The relative uncertainties of the ALI of the test samples are determined to be in a range from 4.1% to 5.5% (k=2), but most of their dominant uncertainty components turn out to be systematic and correlated. In conclusion, correlations between the uncertainty components critically affect the overall uncertainty of the LED measurement using a spectroradiometer.     

Evaluation of the measurement uncertainties in the conducted emissions from adjustable speed electrical power drive systems

This paper deals with the evaluation of the uncertainties involved in the measurement of conducted emissions from adjustable speed drives. Besides the measurement uncertainty due to all the components of the measurement chain, the uncertainties arising from nonrepeatability and from both the configuration setup and the operating conditions were investigated. Following the test arrangements suggested by the electromagnetic compatibility standards, a detailed analysis and quantification of the effects of the reciprocal position of the power and of the motor cables, of the motor cable lengths, and of the pulse width modulation switching frequency used in the test were carried out.     

Uncertainty considerations in AC loss measurement of multifilamentary superconducting wires performed via a pickup coil method

The uncertainty of AC loss measurements for multifilamentary superconducting wires by a pickup coil method is evaluated on the basis of the law of propagation of uncertainty. In this evaluation, the effects of measurement conditions, signal processing, and the division of the AC loss into its components (hysteresis loss and coupling loss) are taken into account as elements of uncertainty. The effect of the measurement conditions is evaluated using theoretical expressions of the two main components. Additionally, the effect of signal processing is considered in accordance with the actual processes of the AC loss measurement using experimental outputs. The main factors that contribute to the uncertainty in the propagation process are discussed. The estimated resultant uncertainties are compared to experimental ones for round robin tests of AC loss measurement of Nb-Ti multifilamentary wires exposed to an alternating transverse magnetic field.     

超高效液相色谱质谱法测定水产品中恩诺沙星含量的不确定度评价

采用超高效液相色谱质谱法测定水产品中恩诺沙星的含量,分析不确定度的来源,建立评估的数学模型,通过计算不确定度的各主要分量,给出了测定结果的扩展不确定度.评定结果表明:影响检测结果不确定度的主要因素为标准溶液的配置、样品的回收率和测量重复性等.     

测量不确定度评定及其应用

测量不确定度评定的方法在许多书籍和文章中均有介绍,本文试图从其应用的角度,通过棉纤维手扯长度测量不确定度的评定方法示例,介绍测量不确定度的评定方法及其在实验室间比对结果评价分析上的应用。     

生活饮用水3M Petrifilm~(TM)菌落总数测试片法的不确定度评定

对3M PetrifilmTM菌落总数测试片法检测生活饮用水中菌落总数的测量结果进行了不确定度评定,评述了引起测量结果不确定度的主要因素,对样品稀释及方法精密度因素进行了详细评价,并对单一样品重复测量10次及30个样品每个样品平行测量2次的两种情况,分别进行了重复性标准偏差评价。结果显示:单一样品重复测量时,测量结果的不确定度主要由样品稀释和重复性标准偏差引起,扩展不确定度U95为20CFU/mL,k=2;多个样品每个样品平行测量2次时,测量结果的不确定度主要由重复性标准偏差引起,在95%的置信度时,扩展不确定度U(lgxj)为0.093,k=2.75。     

生活饮用水3M Petrifilm^TM菌落总数测试片法的不确定度评定

对3M PetrifilmTM菌落总数测试片法检测生活饮用水中菌落总数的测量结果进行了不确定度评定,评述了引起测量结果不确定度的主要因素,对样品稀释及方法精密度因素进行了详细评价,并对单一样品重复测量10次及30个样品每个样品平行测量2次的两种情况,分别进行了重复性标准偏差评价。结果显示：单一样品重复测量时,测量结果的不确定度主要由样品稀释和重复性标准偏差引起,扩展不确定度U95为20CFU/mL,k=2;多个样品每个样品平行测量2次时,测量结果的不确定度主要由重复性标准偏差引起,在95%的置信度时,扩展不确定度U（lgxj）为0.093,k=2.75。     

Effects of densitometry,material mapping and load estimation uncertainties on the accuracy of patient-specific finite-element models of the scapula

Patient-specific biomechanical models including patient-specific finite-element (FE) models are considered potentially important tools for providing personalized healthcare to patients with musculoskeletal diseases. A multi-step procedure is often needed to generate a patient-specific FE model. As all involved steps are associated with certain levels of uncertainty, it is important to study how the uncertainties of individual components propagate to final simulation results. In this study, we considered a specific case of this problem where the uncertainties of the involved steps were known and the aim was to determine the uncertainty of the predicted strain distribution. The effects of uncertainties of three important components of patient-specific models, including bone density, musculoskeletal loads and the parameters of the material mapping relationship on the predicted strain distributions, were studied. It was found that the number of uncertain components and the level of their uncertainty determine the uncertainty of simulation results. The ‘average’ uncertainty values were found to be relatively small even for high levels of uncertainty in the components of the model. The ‘maximum’ uncertainty values were, however, quite high and occurred in the areas of the scapula that are of the greatest clinical relevance. In addition, the uncertainty of the simulation result was found to be dependent on the type of movement analysed, with abduction movements presenting consistently lower uncertainty values than flexion movements.