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荧光量子效率是发射与吸收的光子数之比,是表征荧光材料发光性能的关键参数。然而,用于绝对法测量荧光量子效率的光路和探测器未经校准溯源或是校准方法不当,会造成测量光谱的不准确,进一步影响荧光量子效率计算结果的不准确。采用汞氩灯对单色仪进行校准,保证了激发波长和发射波长的准确性,利用标准辐射源对光路、发射单元单色仪和探测器进行光谱相对强度校准,保证了激发波段和发射波段光谱相对强度的准确性;最后从测量模型出发,对测量不确定度进行了分析,得到在300~360nm的激发光波段和370~900nm的发射光波段内相对合成标准不确定度为3.58%,相对扩展不确定度为7.16%,k=2。通过对单色仪波长校准以及对光谱相对强度进行校准,为荧光量子效率的准确测量提供了参考。 相似文献
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介绍了LTD500/LTD640/AT901-B激光跟踪仪示值校准结果的测量不确定度的评定过程,并验证了该方法的可靠性。对于目前激光跟踪仪示值校准过程的解决方案提出了一些自己的见解。即:如何在确保系统精度符合性要求的前提下,依据激光跟踪仪的用户的实际使用状况及各项标准测量不确定度的分量对测量结果影响的权重,来有效地选用校准仪器和确定被校仪器其校准项目及校准方法。 相似文献
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测量审核指通过两个实验室间的比对,按照预先制定的准则评价参加者的能力。本文针对实验室参加微波功率校准能力的测量审核,对功率敏感器校准因子的不确定度进行评定,详细分析了校准过程中的影响因素,并提出了解决方案。测量审核结果为满意。 相似文献
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本文从音准仪的定义、使用范围的表述引伸到不确定度评定时典型参数和单位与量的选择、数学模型的确定以及测量方法的简单论述,并选择了比较常用具有代表性的指针式音准仪进行校准和不确定评定。对标准音高测量重复性进行A类评定的标准不确定度与采用B类方法评定的音准仪标准音高指示零线重合偏差标准不确定度之间的相关性进行了讨论。通过不确定度评定实例,得到肯定结论:频率最大允许误差为±n×10-6、分辨力为1mHz的频率合成标准信号发生器可以校准允差为±1音分或±2音分的指针式音准仪;指出影响测量扩展不确定度的两个关键因素并为校准更高准确度的音准仪给出了有效方法和关键措施。 相似文献
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1954年Zin E和Forger K成功研究出互感器串并联电压加法线路;1988年国家高电压计量站成功研究出互感器双边串联电压加法线路,2006年使用串联型电压互感器进行双边电压加法,2008年试验电压达到1000/3kV,电压比不确定度不大于4×10-5(P=95%)。要进一步减小电压比的不确定度,需要最大限度地消除串联型电压互感器的屏蔽误差以及邻近干扰误差。除了设计电磁屏蔽更完善的串联型电压互感器外,还可以使用三端口网络理论实施电压加法,通过三端口网络的响应叠加性,使得在加法过程中的屏蔽误差和邻近干扰误差很大程度上得到补偿。2013年使用广东电网电力科学研究院的500kV工频电压比例自校系统装置进行了验证试验。与1988年数据相比,110/3kV电压下的屏蔽误差从18×10-6减小到1.5×10-6,与2006年数据相比,500/3kV电压比例不确定度从15×10-6减小到7×10-6(P=95%)。 相似文献
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能量天平法作为一种质量量子基准研究方案,其中磁链差测量是能量天平测量过程的核心,其基本原理是对线圈感应电压的时间积分进行测量。原有的磁链差测量方法是基于数字积分原理的,当其应用于能量天平同步测量方法中时,难以克服数据采集卡的本征弱点,无法满足10-8量级的相对标准不确定度需求。为此,基于双积分型模数转换器(ADC)提出了一种模拟积分测量原理的磁链差测量方法。该方法利用双积分型ADC的模拟积分测量特性,消除原方法中电平保持采样过程引入的测量误差;通过定序触发多个并联的ADC进行接续测量,去除ADC数字量化过程引入的测量死区;配合使用多ADC分时清零方法,抑制时变噪声累积导致的测量分散性。测试结果表明,在同步测量过程中应用上述方法之后, 磁链差测量的相对标准不确定度由原来的10-6量级抑制至1.7×10-8。 相似文献
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Brandolini A. Faifer M. Ottoboni R. 《IEEE transactions on instrumentation and measurement》2009,58(5):1345-1353
The calibration of measurement transformers represents a classical task in the practice of electrical measurements. Most commercial instruments that are expressly designed for this purpose found their working principle on a scheme that is based on the idea of Kusters and Moore. Although they can assure very high accuracy, the need to employ a high-performance electromagnetic circuit makes them very expensive and usually not suitable for measurements at frequencies that are higher than 50 or 60 Hz. For this reason, these kinds of instruments cannot be employed for the calibration of the new generation of current and voltage transducers, such as electronic measurement transformers, whose employment is growing in all the applications where wide bandwidth is required. In this paper, a new method for the calibration of electromagnetic voltage and current measurement transformers (VTs and CTs) and electronic voltage and current measurement transformers (EVTs and ECTs) is discussed, and a deep metrological characterization is carried out. The novelty of the proposed method is represented by a completely different approach to the measurement of the ratio and phase errors of the measurement transformers. The method is based on the proper digital signal processing of the signals that are collected at the secondaries of the transformer under test and of a reference transformer when the same signal is applied to their primary. Since no auxiliary electromagnetic circuits are required, this solution can be easily implemented in a simple and cost-effective way. In spite of its simplicity, the tests that are developed on a prototype clearly point out that the proposed system is suitable for the calibration of measurement transformers with precision class up to 0.1 in the frequency range from 50 Hz to 1 kHz. 相似文献
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Low frequency (LF) voltage and current are important parameters in electrical metrology. The standards for LF voltage and current are established by assigning AC–DC transfer difference to thermal devices, i.e. thermal converters or thermal transfer standard along with current shunts. Automated calibration systems have been developed based on Null method and measurement technique developed by Budovsky for calibration of precision calibrator in LF voltage and current against thermal devices. The technique based on the Algorithm developed by Dr. Ilya Budovsky (National Metrology Institute (NMI), Australia) has been compared with the conventional null technique. Indigenously developed software has been used to calibrate the precision calibrator in the entire LF voltage and current range using Holt thermal converters and current shunts. Calibration results at 1 V, 10 V in the frequency range from 10 Hz to 1 MHz as well as calibration results of 1 A in the frequency range from 40 Hz to 10 kHz are presented in this paper. These result shows that the measurement technique developed by Budovsky has reduced the complexity of AC–DC transfer measurements, measurement time and the uncertainty in measurement. 相似文献
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