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《中国测试》2016,(8):48-52
建立甲醇中氯苯溶液标准物质的研制及不确定度评定方法。使用气相色谱(GC)和液相色谱(HPLC)两种不同方法精确测定氯苯主成分含量,电感耦合等离子体质谱仪(ICP-MS)和卡尔·费休水分仪(KF)测定无机杂质和水分含量,并最终通过质量平衡法对氯苯纯度进行准确定值。采用重量-容量法制备特性量值为10.0μg/m L的甲醇中氯苯溶液标准物质,其主要用于污染物中氯苯的成分分析、环境评价以及相应分析方法的确认等,制备的标准物质均匀性和稳定性良好,定值结果的相对扩展不确定度为U=3%(k=2),有效期限24个月,通过与同类国家标准样品甲醇中氯苯GSB 07-1220——2000量值比对,验证制备方法定值结果的准确性。 相似文献
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介绍了参加国际物质量咨询委员会(CCQM)组织的K93氮气中乙醇制备比对的过程,包括纯气分析、氮气中乙醇的制备方法,分析方法以及不确定度评价。根据主导实验室给出的比对结果显示,此次的比对获得了较好的结果。通过比对得到的数据,验证了我国制备乙醇混合气体的能力,同时也很好地支持了相关的CMC项目申报。 相似文献
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采用GB/T 17657-2013《人造板及饰面人造板理化性能试验方法》中的干燥器法,对卫浴家具中人造板甲醛释放量的检测过程进行试验研究,并依据JJF 1059.1-2012《测量不确定度评定与表示》分析影响甲醛释放量测定的各种不确定因素,量化和评定各不确定度分量。结果表明:甲醛释放量为(1.06±0.05)mg·L-1,扩展不确定度的包含因子k=2,其置信概率P=95%。经分析,由标准物质认定值和样品的重复测定引入的不确定度最大,其次为标准曲线拟合的变动性所引入的不确定度。 相似文献
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介绍了影响微量一氧化碳气体标准物质定值的因素,包括定值方法的选取、原料气的选择、纯度检验和称量的方法。分别采用气相色谱仪的FID和PD—HID检测器对标准物质进行检测,确立了该标准物质的分析方法。对称量法制备微量一氧化碳气体标准物质过程中影响测量不确定度的因素进行了分析,评定了标准物质的不确定度。 相似文献
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《中国测试》2016,(5):56-60
建立碘离子溶液标准物质的制备方法及不确定度评定模型。采用质量-容量法制备特性量值为10μg/m L的碘离子溶液标准物质,该标准物质以高纯碘化钾为原料,经IC、ICP和ICP-MS 3种方法分析检测扣除其杂质,并且通过干燥减重法扣除其水分含量,精确测定碘化钾的纯度。制备的碘离子溶液标准物质均匀性和稳定性良好,定值结果的相对扩展不确定度为U=2%(k=2),有效期限为12个月,与同类标准样品GSB 04-2834-2011进行比对分析,结果显示,在规定的不确定度范围内量值具有一致性。该碘离子溶液标准物质可用于环境水质、食品安全等领域的安全检测及相应分析方法的确认与评价。 相似文献
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通过对分光光度法测定地质样品中钼元素质量比全过程分析,确定了测定结果不确定度的来源并加以评定。采用最小二乘法对标准曲线进行线性回归,通过对2个不同质量分数样品的不确定度评定,证明样品的重复性测定和标准曲线拟合引入的不确定度为总不确定度的主要贡献者,且样品Mo质量分数越低,其相对不确定度越大,这与实验室中的实际测定情况一致。 相似文献
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为了准确评估X射线剂量监测用防护仪表的校准因子的不确定度,依据有关技术规范,用标准电离室对参考点位置处的剂量当量率参考值进行测量;采用替代法获得待校仪表的显示值,从而确定校准因子结果的相关影响因素,并分别对影响量的不确定度进行评定;得出仪表校准因子的相对扩展不确定度为5.0%(k=2)。影响校准因子不确定度的主要来源包括校准用辐射场的均匀性、标准电离室本身的刻度因子及能量响应、剂量当量转换因子、待检仪表显示值的统计标准偏差等。在对该类仪表的校准过程中,通过提高标准参考值的不确定度水平可以改善校准因子的不确定度。 相似文献
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通过对高效液相色谱法测定葡萄酒中合成色素苋菜红质量浓度的全过程分析,确定了测定结果不确定度的来源。采用计量学不确定度传递模型,对引入的不确定度分量进行评定,确定了葡萄酒中苋菜红质量浓度标准不确定度由标准物质、标准溶液配制、标准曲线拟合、样品制备、测量重复性和回收率等6部分不确定度合成得到。2个不同质量浓度样品测定结果不确定度被评定,其相对扩展不确定度分别为2.6%和2.2%(k=2),由不确定度评价结果分析得到,样品重复性测定和标准溶液配制是测定结果不确定度的主要来源。 相似文献
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The intrinsic wavelength scale in a modern reference laser-controlled Michelson interferometer-sometimes referred to as the Connes advantage-offers excellent wavelength accuracy with relative ease. Truly superb wavelength accuracy, with total relative uncertainty in line position of the order of several parts in 10(8), should be within reach with single-point, multiplicative calibration. The need for correction of the wavelength scale arises from two practical effects: the use of a finite aperture, from which off-axis rays propagate through the interferometer, and imperfect geometric alignment of the sample beam with the reference beam and the optical axis of the moving mirror. Although an analytical correction can be made for the finite-aperture effect, calibration with a trusted wavelength standard is typically used to accomplish both corrections. Practical aspects of accurate calibration of an interferometer in the UV-visible region are discussed. Critical issues regarding accurate use of a standard external to the sample source and the evaluation and selection of an appropriate standard are addressed. Anomalous results for two different potential wavelength standards measured by Fabry-Perot interferometry (Ar II and (198)Hg I) are observed. 相似文献
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《IEEE transactions on instrumentation and measurement》1970,19(4):239-245
The greatest inaccuracy in making a microwave power measurement is usually the uncertainty of the calibration factor or the effective efficiency. These terms account for the RF losses and substitution errors in the bolometric or electrothermic mount. A new method for transferring calibration from a standard mount to a mount to be calibrated has production line speed and simplicity; yet its accuracy rivals standards laboratory techniques. This method uses an automatic network analyzer to measure the quantities required and to solve the mismatch equation in transferring calibration from the standard mount to the one to be calibrated. A technique is also described to evaluate the errors of the transfer measurement. An accurate method of measuring the complex reflection coefficient of a stabilized source is another result of this work. The present implementation measures effective efficiency, calibration factor, and the magnitude and phase of the reflection coefficient of a mount at six calibration frequencies in 60 seconds. The uncertainty in transferring calibration factor and effective efficiency is about 0.5 percent. 相似文献
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柴油中脂肪酸甲酯含量的测定广泛采用红外光谱法,针对此方法的检测能力和准确性进行了研究。试验测定红外光谱法检测柴油中脂肪酸甲酯的检出限和定量限分别为0.0066g/L和0.0220g/L,加标回收率为99.2%~101.3%,结果表明试验方法具备良好的准确性,能够准确灵敏地检测柴油中脂肪酸甲酯。测定的合成相对标准不确定度为0.0123(置信概率取95%,包含因子k=2),脂肪酸甲酯含量为(3.960±0.097)g/L。分析结果表明标准溶液配制和待测样品配制为引入不确定度的主要因素。 相似文献
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An accurate and precise measurement of selenium in Standard Reference Material (SRM) 3149, a primary calibration standard for the quantitative determination of selenium, has been accomplished by instrumental neutron activation analysis (INAA) in order to resolve a question arising during the certification process of the standard. Each limiting factor of the uncertainty in the activation analysis, including the sample preparation, irradiation, and γ-ray spectrometry steps, has been carefully monitored to minimize the uncertainty in the determined mass fraction. Neutron and γ-ray self-shielding within the elemental selenium INAA standards contributed most significantly to the uncertainty of the measurement. An empirical model compensating for neutron self-shielding and reducing the self-shielding uncertainty was successfully applied to these selenium standards. The mass fraction of selenium in the new lot of SRM 3149 was determined with a relative standard uncertainty of 0.6%. 相似文献