共查询到19条相似文献,搜索用时 203 毫秒
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目的为提高金属包装罐双酚S迁移量测定的实验过程管理和报告评估水平,建立双酚S迁移量测量的不确定度评定方法。方法采用高效液相色谱-串联质谱法检测双酚S在体积分数为4%乙酸食品模拟物中的迁移量,结合JJF 1059.1—2012《测量不确定度评定与表示》规定的方法和步骤,建立不确定度评定的数学模型。根据测量模型,分析影响测量不确定度的主要输入量,对各不确定度分量的数值进行计算,对测量结果进行评估。结果实验中金属包装罐双酚S迁移量测量不确定度报告结果为(2.25±0.302)mg/g,k=2。结论不确定度评估分析表明,检测仪器分量、校准曲线拟合分量和标准溶液分量是最主要影响因素。 相似文献
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频率测量结果的不确定度是频率测量系统测量质量的重要指标,按照不确定的A类和B类分量的评定方法,本文分析了用频标比对法对高精度频率源进行测量时各种因素影响引入的不确定度,并提出了该方法测频的不确定度评定公式,同时又给出了频率源老化率指标的不确定度评定方法.实验表明,本文的不确定度分析方法是正确和有效的. 相似文献
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建立高度卡尺示值误差测量不确定度的测量模型,对高度卡尺测量过程中引入的不确定度进行分类和量化,较为全面地评定了各个不确定度分量,并得出测量结果的扩展不确定度。 相似文献
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《福建分析测试》2020,(2):21-26
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。 相似文献
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通过对电能表检定装置检定电能表基本误差,测量不确定度评定的二种方法的介绍,论证了电能表基本误差测量不确定度直接用基本误差测量重复性引入的标准不确定度分量,与电能表检定装置量传误差引入的标准不确定度分量的方和根合成是可以的,并给出了其理论根据。 相似文献
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金属材料规定非比例延伸强度测量结果不确定度评定 总被引:1,自引:0,他引:1
讨论了目前对金属材料规定非比例延伸强度Rp0.2的不确定度评定的局限性,通过分析GB/T 228-2002中非比例延伸力值的确定过程,将引伸计标距引入的不确定度、引伸计测量引入的不确定度和基准线确定引入的不确定度三个不确定度分量统一到一个模型中,并合成为由引伸计引入的标准不确定度,从而解决了目前对引伸计引入的三个不确定度分量没有数学模型的问题,确定了新的Rp0.2不确定度评定方法,并运用到实例中进行了计算。 相似文献
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基于商用坐标测量机的3D微纳米计量 总被引:1,自引:0,他引:1
以测量精度为1μm的商用坐标测量机(CMM)为基础,构建了测量范围为25mm×40mm×25mm、测量不确定度约为O.15μm的PTB微纳米专用坐标测量机.研究了CMM的运动控制系统、恒温室的空调系统以及CMM的被动隔振系统等对测量结果的影响.由测量结果可以看出,CMM的运动控制系统产生的噪声水平约为其他误差源的2倍.通过FFT运算,发现未优化系统的短时最大漂移量发生频率为750Hz,对应为运动控制的工作频率.文中还介绍了测量力为1州光纤探针的测量原理,并给出了对2.5mm短轴的测量结果. 相似文献
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Uncertainty estimation in coordinate measuring machine (CMM) measurements is one of the highest priority tasks in modern industrial world due to its importance in the manufacturing metrology, especially if we take into account the fact that workpieces, according to a new generation of geometrical product specifications, can be accepted/rejected only on the basis of the total measurement results. Evaluation of measurement uncertainty of a CMM is a complex task, especially in the verification of errors of forms. Among several standard methods that can be used to estimate measurement uncertainty, we performed a comparison between two of these for the case of flatness measurement. Optical flat was used in order to exclude a number of essential factors in the case study. The results showed that the expanded measurement uncertainty assessed by GUM is greater than the value of the expanded measurement uncertainty obtained using the ISO 15530 method. However, both methodologies have shown that the maximum permissible error of a CMM has the greatest impact on uncertainty and also, that the total result evaluated by both approaches is close to the maximum permissible error of a CMM. 相似文献
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An improvised Zirconia-Dolerite ball plate artefact is manufactured, which computes different geometric errors of CMM in three different plane positions (XY, YZ and ZX). Uncertainty measurement of this artefact will affect calibration of CMM. CMM undergoing periodic interim checks by ball plate measurement needs to compute uncertainty analysis over a calibration period. This requires repetitive measurements of artefact, involving great measurement cost. An attempt has been made in this research work to devise Monte Carlo framework (MCF) for analyzing the uncertainty of ball plate measurement. The presented MCF requires less repetitive measurement at actual. This work also made possible to find preferable zones of measuring areas of CMM including volumetric measurement, explaining novelty of the research work. In the present test specific CMM, demonstrated MCF recommends seldom use of lower left corner of CMM. 相似文献
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坐标测量机的溯源方法 总被引:2,自引:0,他引:2
由于坐标测量机的通用性,不同的测量任务有不同的测量不确定度,长度测量不确定度可以作为坐标测量机溯源的近似方法,但面向任务的校准则是最终的解决方案。文中还介绍了中国计量科学研究院提出的目前条件下的坐标测量机溯源方案。 相似文献
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双目立体视觉是一种商业化较成熟的三维测量技术,左右摄像机内外参数的精确标定是实现三维重构的基础和关键。针对棋盘格和圆点两种标定板图案研究了相应的图像处理技术,实现了标定点的亚像素精度定位及其有效排序。采用基于单映性约束和非线性优化的多视角平面标定算法实现了摄像机光学及空间位置参数求解。用极线约束残差法衡量标定结果的准确度。基于桥式三坐标标准实现标定点三维重构平面度以及多平面空间夹角测量结果的校准,基于光学三坐标标准实现了标定点三维重构空间距离的校准,并分析了校准结果的不确定度。圆标志点三维重构空间距离示值误差为0.029 mm,不确定度U=24 μm(k=2) 相似文献
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In the coordinate measuring machine (CMM) measurement environment, uncertainty can arise from various sources. Previous literature has focused on how to measure uncertainty in a CMM system using segregated approaches. We developed a framework to verify bias and variance tendencies deriving from form errors. Two types of form tolerances, namely flatness and circularity, are addressed here. By studying the nature of the CMM measurement uncertainty impact, this paper targets three objectives: (1) developing a design of experiments (DOE)-based measurement performance approach to integrate critical measurement strategy factors; (2) optimizing identified controllable measurement factors; and (3) synthesizing the impact of CMM uncertainty issues. Consequently, the paper fully explores the influence and interplay of these contributing factors, resulting in robust and optimal guidelines for the CMM flatness and circularity measurement strategy. Extensions of the framework for other form tolerances are discussed. 相似文献
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该文介绍坐标测量机与激光干涉仪对步距规进行校准的测量原理和测量过程,测量结果与DKD证书进行对比,并分析测量结果的不确定度。 相似文献
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One of the main tasks of the quality test is the inspection of all relevant geometric parts related to the predefined tolerance range, whereas the uncertainty of measurement has to be less than the tolerance range. The reachable uncertainty of measurement can be determined using method A of the ISO Guide to the Expression of Uncertainty in Measurement (GUM), which is expensive and time consuming and has to be carried out for each individual metrologic case. Furthermore, it is possible to check the suitability of the measurement system for the planned inspection using virtual measurement techniques and therewith to reduce the time and money spent. This means that the uncertainty of measurement is estimated using method B of the GUM. In this paper, a virtual fringe projection system is used for the estimation of the uncertainty of measurement, which is compared with the uncertainty of measurement determined with a real measurement system using method A of the GUM. With the presented method, it is possible to calculate an optimal measurement position within the measurement volume, based on a minimum uncertainty of measurement. Thereby, the influence of the operator related to the uncertainty can be significantly reduced. 相似文献