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在计量标准考核和计量标准复查的工作中,通常需要提供稳定性试验数据,以保证计量标准的准确性。计量标准的稳定性是指用该计量标准测量稳定的被测对象时得到的测量结果的一致性。新建计量标准一般应经过稳定性考核,证明其所复现的量值稳定可靠后,方能申请建立计量标准。已建计量标准应有历年的稳定性考核记录,以证明其计量特性的持续稳定。依据GJB/J2 74 9- 96《建立测量标准技术报告的编写要求》,测量标准的稳定性用实验标准偏差Sm 定量表征。稳定性评定,可选一稳定的被测对象或被检测量器具,如核查标准或传递标准,每隔一段时间(大于一个… 相似文献
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中国计量科学研究院正在建立保护热板法测量固体材料导热率的标准装置,本文对实验原理、装置与实验过程作了简单的介绍,在室温至80 ℃温度范围内对PTB提供的标准参考物质进行了多次导热率测量,对测量结果进行拟合的相对标准偏差为0.6×10-2W/(m·K),并与欧洲实验室的测量结果进行对比;在80 ℃~530 ℃温度范围间测量了花岗岩材料的导热率,测量的结果随着温度的上升而下降. 相似文献
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Excel在电能计量标准检定和建标中的应用 总被引:1,自引:0,他引:1
本文主要介绍使用Excel电子文档编写电能表标准装置的检定报告和电能表标准装置的建标技术报告.在一个Excel工作簿中,设计电能表标准装置的检定原始记录表格,利用它的计算功能来实现平均值的计算,实验标准偏差的计算,并在同一个Excel工作簿中,利用它的单元格引用和函数功能来实现检定报告的编写;在一个Excel工作簿中,设计电能表标准装置的计量标准技术报告的表格和内容,利用它的计算功能来实现平均值的计算,实验标准偏差的计算和结果的判断,稳定性的计算和结果的判断,测量不确定度评定中合成标准不确定度和扩展不确定度的计算. 相似文献
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短程光电测距仪测距标准偏差的野外测定方法--介绍国际标准ISO12857-3:1997(E) 总被引:1,自引:0,他引:1
测距标准偏差是表征光电测距仪的综合技术指标,ISO12857-3:1997(E)标准是野外测定短程光电测距仪测距标准偏差的最新国际规范,它对野外测定短程光电测距仪测距标准偏差的适用范围、标准基线设计、测量和数据处理方法以及统计检验规则进行了规定。 相似文献
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文章主要阐述单次测得值的实验标准偏差及意义,在规范化的常规测量中,可以事先对测量重复性进行预评估,并将单次测得值的实验标准偏差和平均值的实验标准偏差作具体比较,利用预评估重复性进行A类评定标准不确定度的计算。 相似文献
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使用经纬仪、激光跟踪仪进行协同测量时需要对不同测量系统的测量基准进行基准转换,传统基准转换手段较为繁琐耗时。针对此问题,设计了一种新型便携式基准转换标准器,该标准器由基准转换组件、转向组件和三脚架组成,通过基准板上的测量靶点及立方镜构建坐标系,实现基准转换。经验证:该标准器在不同姿态下的平均位置偏差小于0.01 mm,利用基准转换标准器验证了经纬仪系统定位孔中心点的测量偏差均小于0.06 mm,立方镜法矢量的平均绝对偏差小于0.0043°。结果表明,该标准器操作方便快捷,能够满足不同工况下经纬仪与激光跟踪仪协同测试的基准转换需求,具有应用推广价值。 相似文献
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Peter H. Huang Raghu Kacker 《Journal of research of the National Institute of Standards and Technology》2003,108(3):235-240
Permeation-tube moisture generators are used in industry as calibrated sources of water vapor and carrier gas mixtures. Measurements were made using three permeation-tube moisture generators of the type used in the semiconductor industry. This paper describes repeatability and reproducibility standard deviations in measurement of moisture concentration from such generators. Repeatability refers to measurements within a system and reproducibility refers to measurements between systems. Two independent methods were used to measure the realized concentration of water vapor. The first measurement, the calculated value, was determined using calibrated permeation rate of permeation-tube and flow rate of dry carrier gas. This is the industrial method of evaluating moisture concentration. The second measurement, the measured value, was determined using the low frost-point generator at the National Institute of Standards and Technology (NIST) and a quartz-crystal-micro-balance. Four pairs of independent measurements for each generator and for six nominal levels in the range from10 nL/L to 100 nL/L were made. The characteristic used to quantify repeatability and reproducibility standard deviations in industrial measurements is the calculated value minus the measured value. Repeatability standard deviation ranges from 1 nL/L to 2 nL/L, approximately. Reproducibility standard deviation ranges from 2 nL/L to 8 nL/L, approximately. The documentary ASTM standard E691-99 was used for both data validation and quantification of the repeatability and reproducibility standard deviations. 相似文献
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研制和改进了基于传感器辅助方法的活塞式压力计自动化校准系统,介绍了基于LabVIEW编制的校准软件的组成和功能。通过与传统方法的比对,实验研究了自动校准系统应用于气体活塞式压力计国家基准量值传递工作的可靠性。研究表明,传感器系数γ与1的偏差和相对压差β的乘积小于10-6时,γ可作为1处理;测量上限为7MPa的反压型气体活塞,全量程和半量程的拟合数据表明活塞的压力形变具有一定的非线性,因此对于高压活塞应进行全量程校准;PG7607活塞底座发热导致0.33 ℃的活塞温度测量误差,由此产生3×10-6的压力测量误差,对于压力基准是不可忽略的;180kPa、360kPa和3MPa 活塞的2种方法校准结果偏差分别约为标准不确定度的10%、1%和2%,验证了自动化校准系统的高可靠性。 相似文献
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一种测量透明平行平板折射率的新方法 总被引:1,自引:0,他引:1
通过测量激光细光束经平行平板玻璃所产生的位移,可确定平行平板的的折射率。本文阐述了该方法的测量原理,给出了测量公式,并详细分析了测量误差。计算机模拟计算结果表明,当平板厚度为50mm时,如果入射角测量标准偏差为1”,平板厚度和光线位移量测量标准偏差均为0.001mm,则折射率测量的标准偏差可达6×10~(-5),此时入射角约55°。 相似文献
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Application of the astigmatic method to the thickness measurement of glass substrates 总被引:1,自引:0,他引:1
We developed a high accuracy thickness measurement system for glass substrates based on the optical design of the astigmatic method. The astigmatic optical system includes a laser diode, a cylindrical lens, a convex lens, and a quadrant detector. This method measures the astigmatic focusing error signal induced from the measured glass placed in the astigmatic optical system. The astigmatic focusing error signal is converted into the thickness of the glass substrate. The proposed glass thickness measurement system is verified by using a coordinate measuring machine (CMM). The accuracy of the proposed system is 0.2 microm, with a standard deviation of 0.7 microm within the thickness measuring range of 1.2 mm. 相似文献
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Local Particle Mean Velocity Measurement in Pneumatic Conveying Pipelines Using Electrostatic Sensor Arrays 总被引:1,自引:0,他引:1
In this paper, a measurement system for the local mean velocity of pneumatically conveyed particles is proposed and developed. It mainly consists of electrostatic sensor arrays, signal conditioning circuits, and a digital signal processor (DSP)-based data acquisition and processing unit. Electrostatic sensor arrays are used to detect the charge on particles in its sensing zone and further make the local particle mean velocity measurement in conjunction with cross-correlation method. The sampling frequency is determined from theoretical analysis of the bandwidth of electrostatic signal and accuracy of correlation velocity calculation. Experiments are carried out on a belt conveyor and a gravity-fed particle rig to determine the optimized sampling number of the electrostatic signal through analyzing the measurement error of the transit time. The results showed that the more sampling numbers, the higher stability of measurement results. The repeatability of the measurement system is less than ±2.2% and the linearity is better than ±4.9% over the velocity range of 5.50–21.98 m/s. Experiments are also performed on a high-pressure dense-phase pneumatic conveying system of pulverized coal, indicating that the measurement system is capable of achieving local mean velocity measurement of pneumatically conveyed particles with the relative standard deviation less than 5.5%. 相似文献