电线拉伸实验不确定度分析

1999年国家质量技术监督局计量司颁发JJF 1059-1999《测量不确定度评定与表示》,但广大检测实验室依然对"不确定度"知之不多,所进行的"不确定度"分析、计算、表示,也仅仅存在于校准实验室;本文仅就检测实验室的检测项目进行"不确定度"分析。     

耐热(球压)试验压痕直径的测量不确定度评定

阐述了评定测量不确定度的必要性;考虑到耐热(球压)试验在电气安全检测实验室中是一个非常典型的安全检测项目,按JJF 1059.1-2012《测量不确定度评定与表示》规定的方法和步骤以及结合本人所在实验室实际情况对该项目进行了测量不确定度的评估。     

校准实验室测量不确定度评定步骤和表示

ＩＳＯ/ＩＥＣ 1 70 2 5国际标准 5 4 6 1中规定 :校准实验室或进行自校的检测实验室必须对所有校准项目和校准类型制定并实施测量不确定度评定的步骤。而且对校准而言 ,该步骤对各类校准是一致的 ,对检测实验室 ,该步骤则因不同的检测项目和类别会有所区别。例如 :有的检测包括取样和样品制备 ,有的则不包含这两个步骤。对校准实验室测量不确定度评定的步骤 ,目前国内还没有作出统一规定 ,本文参考欧洲实验室认可合作组织 (ＥＡ)推荐的六个评定实例 ,归纳了如下评定步骤 ,供有关人员参考。另外 ,我国对如何表述实验室的测量不确定度能力说…     

对测量过程的计量要求导出及测量不确定度评定的探讨

正对检测实验室而言,测量是需要使用测量设备确定量值的,通过计量要求导出可以正确选择测量设备;测量不确定度受诸多因素的影响,通过测量不确定度的评定可以定量说明一个实验室的工作水平。为了进一步提升检测工作质量,确保检测数据的科学严谨,现依据认证、认可、标准的有关要求,在计量要求导出、测量不确定度评定以及应用方面进行探讨。     

检测实验室测量不确定度评定工作的反思与探讨

自JJF1059—1999《测量不确定度评定与表示》、GB／T15481—2000《检测和校准实验室能力的通用要求》发布实施以来，以不确定度理论取代传统的误差理论对测量结果进行分析评价，已成为认可实验室的共识与必然要求。但事实上测量不确定度在两类实验室中的应用程度和成效存在着较大的反差：一方面经CNAL认可的校准实验室都在认可项目上，基本完成了不确定度评定的示范，运用水平有了很大提高；而另一方面，大量检测实验室，尤其是电器产品检测实验室，无论是能熟练运用不确定度理论的试验人员数量，还是已应用项目都还不多，只能说仍然处于起步阶段。     

小型变压器绕组温升试验测量不确定度分析与评定

以小型变压器为例,采用电阻法对其绕组进行温升试验。基于分层建模评定方法,详细分析了温升试验测量不确定度的来源。依据国家计量技术规范JJF1059.1-2011《不确定度评定与表示》对其试验结果进行不确定度评定,为检测实验室的不确定度评定工作提供了一定的指导作用,从而能够有效地完成实验室的质量控制管理工作。     

校准实验室测量不确定度评定步骤和表示

ISO/IEC 17025国际标准5.4.6.1中规定:校准实验室或进行自校的检测实验室必须对所有校准项目和校准类型制定并实施测量不确定度评定的步骤.而且对校准而言,该步骤对各类校准是一致的,对检测实验室,该步骤则因不同的检测项目和类别会有所区别.例如:有的检测包括取样和样品制备,有的则不包含这两个步骤.     

检测实验室测量不确定度评定与应用现状

本文综述了目前国内检测实验室不同专业在测量不确定度评定方面的各种现象、思路和操作方式,以及在不确定度应用中面临的市场、标准、技术能力等问题,并分析了这些现象和问题背后的原因,展望了解决这些问题的潜在途径,为实验室更好的利用测量不确定度这一工具量化分析检测工作中潜在的风险和机遇提供了参考。     

基于水中氰化物测量不确定度评定的检测质量管理

通过评定实验室检测的测量不确定度,建立以不确定度指标量化检测质量控制和质量管理效果的方法。以水中氰化物测量不确定度评定为例,采用GUM法和线性拟合法,评定其A类和B类不确定度,着重量化了标准溶液制备、校准曲线回归、检测过程等B类不确度分量,并采用电子表格的统计性能,建立起便于日常检测中快速评定不确定度的方法。实验结果表明,当水样中氰化物的质量浓度为0.125mg/L时,扩展不确定度为0.008mg/L,评定模型中比色管内氰化物的质量引入的不确定度分量最大。评定过程说明了影响实验室检测数据质量的主要因素是人员、仪器、环境、测量方法、取样和以标准物质为代表的试剂;按照RB/T 214-2017的要求对上述因素规范管理,结合本文建立的不确定度动态评定方法,能够保证检测实验室的数据质量。     

低压电器温升试验的不确定度分析

不确定度是国际公认的用来评定测量结果质量的参数，是报告度量的尺度。准确、合理的不确定度评定是提供正确测量结果的前提和保证。本文以低压电器温升试验的不确定度评定为例，分析了检测实验室对产品进行不确定度评定的方法。     

Measurement uncertainty in quantitative chemical analysis: Problems of the transition period

Various aspects of the implementation of the concept of measurement uncertainty in analytical laboratories of Russia are considered. Information on international and identical domestic documents on the estimation and application of measurement uncertainty is presented. The analogy between the transition to the uncertainty concept and the transition to the metric system is drawn.     

Evaluation of laboratory performance through interlaboratory comparison

This paper reports the performance of the calibration results obtained by 21 laboratories using digital pressure calibrator as an artifact in the pressure range 7–70 MPa. National Physical Laboratory (NPLI), New Delhi has coordinated this programme and also acted as a reference laboratory. The program started in May, 2006 and completed during May, 2008. The comparison was carried out at 10 equally spaced pressure points i.e. 7,14,21,28, 35,42,49,56, 63 and 70 MPa throughout the entire pressure range of 7–70 MPa. The calibration results thus obtained were analyzed as per ISO / IEC GUM document. The 92.7 % measurement results are found in agreement with the results of NPLI. The relative deviations between laboratories values and reference values are well within the 0.05 %for 123 measurement points, 0.1% for 162 measurement points and 0.25% for 177 measurement points. The difference of the laboratories values with reference values are found almost well within the uncertainty band of the reference values at 68.0 % measurement results, within their reported expanded uncertainty band at 81.5% measurement results and within the combined expanded measurement uncertainty band at 92.7 % measurement results. Overall, the results are considered to be reasonably good being the first proficiency testing for most of the participating laboratories.     

噪声传递中失配误差的再讨论及解决方案

针对我国实验室噪声传递不确定度较大的问题,以中频衰减法为例,给出噪声传递中失配误差的数学模型。基于无相位信息的复变量不确定度估计的研究成果,给出了失配引入不确定度的最佳估算方法。基于失配不确定度的准确估计,论证了隔离衰减器在噪声测量中的效用及使用策略。最后给出噪声测量中失配误差的最佳解决方案。     

电压驻波比测量不确定度的评定和表述

电压驻波比是无线电领域表征反射特性的传统参量,目前仍有应用场景,然而一些实验室对电压驻波比测量不确定度的报告是不完善的。比较了GUM法线性模型、GUM法非线性模型和蒙特卡洛法对电压驻波比测量不确定度的评定结果,给出了一种在常规测量条件下可代替蒙特卡洛法的快速估算方法,并将该方法推广到一元非线性测量模型。     

Die Kalibrierung von Vakuummessgeräten in Industrie und Forschung

The increasing economic demand for higher measurement accuracy and the demands of modern quality assurance systems require regular calibration of the measuring and testing gauges. Vacuum gauges are more and more utilized as measuring and testing gauges in manufacturing processes and research in order to get reliable and correct product specifications. Systematic and statistical measuring deviations can only be determined through calibration. The reliability of test results is not only dependent on the accuracy, precision, repeatability and reproducibility but also depends on the competence of the tester and correctness of the testing method. Therefore, the confidence in the validity of the measurement results and in the competence of the calibration laboratory is a decisive factor. The calibration of vacuum gauges and the traceability to national standard is done through a series of comparison measurements. The calibration laboratories of the German calibration service (DKD), which are accredited by the Physikalische‐Technische Bundesanstalt (PTB), are distinguished by their technical expertise and high quality standard. The DKD‐calibration certificates offer reliable measurement results including the measuring uncertainty and are accepted by the accreditation bodies of the member states of the European co‐operation for Accreditation (EA). The typical requirements on a calibration laboratory for vacuum gauges are explained exemplarily for the DKD‐calibration laboratory of VACUUBRAND GMBH + CO KG company.     

Comparison of Meteorological Service Calibration Laboratories in Southeastern Europe

Interlaboratory comparisons serve as tools for assessment of measurement results performed by calibration laboratories in the relevant field of measurement. They are effective means to demonstrate technical competence of the participant and are used as a technical base for accreditation. However, in the network of meteorological services calibration laboratories, comparisons among laboratories are still rare. Some laboratories are still not evaluating measurement uncertainty, thus causing problems when comparing meteorological data from different countries. The Environmental Agency of the Republic of Slovenia (EARS), serving in the frame of the World Meteorological Organization as a Regional Instrument Centre, has organized a round-robin comparison of calibration laboratories of meteorological services in the southeastern part of Europe using instruments for temperature, relative humidity, and barometric pressure. Each participant laboratory had to calibrate a set of instruments at defined calibration points, to evaluate the measurement uncertainty (if possible), and to report the results. EARS RIC invited the National Hydrometeorological Services in the southeastern part of Europe to take part in the intercomparison. In addition, the Laboratory of Metrology and Quality (MIRS/UL-FE/LMK), which holds the Slovenian national standard for temperature and relative humidity, was also invited to participate in the comparison and in the data analysis. Results from MIRS/UL-FE/LMK and EARS were used to calculate the temperature and humidity comparison reference values, while the EARS results were taken as reference values for barometric pressure.     

白光干涉测量系统的测量不确定度评定

白光干涉测量系统(white-light interference system, WLIS)广泛用于微纳米表面形貌的精密测量,其测量不确定度评定是研究白光干涉测量系统计量特性的一项重要工作。基于微纳米线间隔和台阶,建立了WLIS测量表面形貌时的测量模型,明确了测量不确定度来源;以5000nm的线间隔和180nm的台阶高度为例,利用WLIS进行了测量,并分析WLIS的测量重复性、光学组件特性、传感器特性、运动模块性能、测试方法及环境等因素产生的不确定度分量,最终评定该WLIS测量线间隔和台阶高度的合成测量不确定度分别为21nm和0.4nm。对WLIS的不确定度评定确保了其测量结果的准确性、溯源性,并提出了提高系统整体计量特性的途径。     

毛细管黏度计校准能力验证

针对毛细管黏度计校准在能力验证中存在的问题,详细分析了校准过程中的影响因素,给出了测量不确定度来源及不确定度评定,有助于提高相关实验室黏度计校准结果的准确度。     

混凝土抗压强度测量不确定度评定

混凝土抗压强度试验是评定混凝土工程质量的重要手段，通过对混凝土抗压强度测量结果不确定度评定，分析了荷载、试件截面尺寸、检验重复性、数据修约等影响测量结果不确定度的因素和来源，对各分量进行了计算合并，并作出了评定，为提高测量水平提供指导。     

测量不确定度评定中忽略相关项所带来的风险评估

在不确定度评定中,相关性问题经常被人为确定,或被故意忽略。这种现象经常发生,尤其是在低端实验室更是如此。这种评定结果将给用户和实验室在测量不确定度的评定中带来一定的风险。文章给出评估这种风险的计算公式,并建议在测量不确定度评定的报告中应给出由于忽略相关性问题而带来的风险的估计值。