分光法测量LED颜色的不确定度分析

分析了分光法测试发光二极管(LED)颜色的测量不确定度,着重分析了光谱功率分布测量不确定度和波长不确定度对颜色测量的不确定度影响,给出了几种典型LED的分析结果,结果表明,5%的光谱功率分布测量不确定度和0.5 nm的波长不确定度在一般情况下可以满足精度要求为0.001的LED颜色测量.     

温度测量的不确定度

通过对影响样品测试结果的因素进行不确定度分量分析和量化的方法,对按照GB4943-2001标准《信息技术设备的安全》中允许的使用热电偶法替代电阻法测量绕组温度的测量结果,进行了不确定度评价。     

测量不确定度及其评定

目前,测量是在科学技术、工农业生产、国内外贸易、工程项目以至日常生活等各个领域中不可缺少的一项工作.测量的目的是确定被测量的量值,测量的质量会直接影响到国家和企业的经营活动.因此,测量不确定度作为衡量测量结果质量的重要指标,对其进行分析研究具有非常重要的意义.本文主要从测量不确定度的发展、定义、来源、分类等方面进行详细...     

光腔衰荡光谱技术用于OH浓度测量的误差分析

光腔衰荡光谱技术（Cavity Ring Down Spectroscopy,CRDS）是一种高灵敏度的吸收光谱测量技术,在燃烧场激光光谱诊断领域里是一种十分重要的燃烧产物定量测量手段。文中研究了光腔衰荡光谱技术用于燃烧产物定量测量的原理,搭建了脉冲型光腔衰荡光谱技术实验系统,选取OHA2+-X2（0,0）电子跃迁带的P1（2）吸收线谱,在常压条件下对平面火焰的OH浓度进行了定量测量,并对激光器线宽及线型、激光器的频率稳定性、火焰温度、光腔参数等因素对测量误差的影响进行了分析讨论。误差分析给出了光腔衰荡光谱技术的几个关键注意事项,可为光腔衰荡光谱技术的应用提供指南。     

基于误差椭球的激光测量系统的不确定度分析

为了对3维激光扫描技术的测量精度做出评估,以激光雷达测量系统为研究对象,基于误差椭球理论建立了测量系统的点位误差模型;依据点云平面误差椭球的分布特性,提出了点云拟合平面的不确定度模型,用于评估与拟合平面关联的尺寸测量精度;通过对箱体类物体高度的测量实验,获得了实际测量不确定度,并与模型仿真结果进行了对比。结果表明,该模型可较准确地估算出高度的测量不确定度,从而验证了其有效性及实际意义。     

辐射场强试验的测量不确定度评定

对10米法半电波暗室的辐射场强试验进行不确定度评定,计算出系统在3m和10m处的不确定度结果．并与相应的标准进行比较后认为该试验系统的测量结果是可信的。     

正入射反射式太赫兹光谱测量的不确定度分析

太赫兹时域光谱技术能够快速、宽频带测量物质在太赫兹频段的光学或介电常数, 是物质识别的重要技术.光学常数的测量准确度完全受到复杂的测量过程和数据处理所影响.针对正入射反射式THz光谱测量, 分析了在测量材料介电特性过程中的误差来源, 它们包括太赫兹幅值误差、位置误差以及样品倾斜误差.建立了单独表征每个误差来源对于光学常数影响的不确定度分量的公式.利用MATLAB仿真了每个误差来源对于光学参数不确定度的影响.     

湿度对近地面大气湍流测量不确定性影响研究

采用多项式法模拟近地面大气湍流,并与实验现场基于温度脉动原理的双点法实测近地面大气湍流进行比对,一方面可以充分利用实验现场的实测温湿压等气象参数进行模拟实验,为研究工作的开展提供便利条件;另一方面可以使研究工作达到科学实际的效果。文中着重研究了在相对湿度较高的环境里实测湍流与多项式法模拟湍流之间的相关性、以及在重新拟合多项式系数后两者之间的相关性变化,从中研究了双点法测量近地面大气湍流的不确定性。分析结果表明:多项式法模拟近地面大气湍流与双点法实测湍流之间在湿度相对较高的环境里相关性较强,且能够维持较高的稳定性,但在相对湿度达到80%以上的环境里两者之间的相关性则明显降低,甚至于出现负值,由此证明双点法测量近地面大气湍流在相对湿度大(80%以上)的环境里存在较大的不确定性。     

基于动态校准测量数据的不确定度评定

提出一种基于比较法的自动式高冲击台的高g值加速度传感器动态校准方法,并针对校准环境的复杂性,标准加速度传感器本身具有的误差性,对校准结果的不确定度进行灰色评定。该方法将校准系统看成为灰色系统,先用灰色准则剔除粗大误差,然后利用灰色方法对校准结果的不确定度进行评定,最后与A类不确定度进行比较,验证了灰色评定方法的可靠性。     

A study on the development of transmission-type extrinsicFabry-Perot interferometric optical fiber sensor

The conventional reflection-type extrinsic Fabry-Perot interferometric (EFPI) optical fiber sensor has good sensitivity and resolution compared with other types of optical fiber sensors. However, they have the disadvantage that the distinction of strain direction of EFPI is difficult because of measurement method by only fringe counting. This paper presents the newly developed transmission-type EFPI (TEFPI) optical fiber sensor, which has been improved by additional functions, and whose measuring system differs from that of the reflection-type EFPI optical fiber sensors using a single-mode fiber (SMF) and multimode (MMF) fibers as light guides and reflectors, respectively. The output signal of the TEFPI optical fiber sensor was analyzed with the uniform plane wave-based model, the SMF power distribution-based model and the splice loss-based model; the analyzed signals were then verified experimentally. Based on the results of analysis, the TEFPI optical fiber sensor was fabricated using two single-mode fibers connected to the light source and optical receiver; this was then used in strain measurement. The strain measured by the TEFPI optical fiber sensor was compared with that measured by the electric strain gauge     

考虑像差影响的透射式光学系统失调校正方法

随着高分辨力光学系统应用领域的不断拓展,光学元件的高精度装配要求和高精度的设计要求一样,已成为光学系统分辨力的决定性因素。现有的高斯光学校正方法仅考虑物像位置关系的调整,已不能满足光学系统的调整要求,光学仪器的调整理论需要同步发展。考虑像差对光学系统失调的影响,提出了一种基于像差理论的(透射式)光学系统失调校正方法:分析了单透镜轴向位移引起的像差变化规律,给出了像差影响系数的定义;在此基础上,通过反演计算像面位置误差和放大率误差所需的透镜调整量,数学推导出了基于像差约束条件的光学系统失调校正公式。以三透镜准直系统为例进行了仿真实验验证,证明了将像差约束引导到校正方法中,能够同时满足高斯光学特性的要求和像差增量最小的要求。     

功率测量误差分析量

无线发射设备的输出功率是所有射频设备中最主要的技术参数,也是用户订购和无线电管理部门关心的关键指标,它直接关系到整个系统的通信质量.     

Uncertainty analysis of the CISPR/a radiated emission round-robin test results

A large round-robin test (RRT) was carried out to obtain quantitative information about the uncertainties that play a role in an International Electrotechnical Commission/International Special Committee on Radio Interference (IEC/CISPR) radiated emission test in the frequency range 30 to 300 MHz. Two different equipment under tests (EUTs) allowed us to distinguish between the measurement instrumentation and the EUT-induced uncertainties, a subset of the standards compliance uncertainties. This paper presents the rationale behind the various RRT-measurements, the way the ancillary equipment was continuously checked, the measurement results and the results of their statistical analysis. The test sites included open-area test-sites, semi-anechoic rooms and fully anechoic rooms. A major conclusion is that measurement instrumentation uncertainty considerations alone cannot explain the uncertainty relevant in an actual CISPR radiated emission compliance test.     

透射式低温光学红外相机全光路冷链热设计

某透射式低温光学红外相机工作于倾斜地球同步轨道,所处空间热环境复杂多变,整个光学路径部组件属于低温光学系统,对温度梯度及温度稳定性要求较高,这对热控系统设计带来挑战。结合相机在轨成像温度需求及空间外热流特点,详细分析了相机热控设计的重点和难点,通过低温热管热量传输和辐射制冷的方式实现了低温光学系统的降温,通过高效热防护、热隔离及间接辐射控温技术实现了低温光学系统的高精度控温。热平衡试验温度数据表明:成像模式下,各光学部组件温度均满足指标要求,光学透镜温度均匀性和稳定性较高,光学透镜间最大温差小于1 K,最大温度波动小于±0.3 K,实现复杂内外热环境下光学透镜高精度控温;加热去污模式下,利用低温热管“热开关”的特点在常温下热阻增加,通过较小热控功耗实现光学透镜加热去污的需求。     

测量方法对测量结果误差影响的分析

本文基于工作实践,分析了测量结果产生误差的原因,除了装置、环境和人员的误差之外,测量方法对测量结果造成的误差影响也是明显的。然后,着重介绍了差值法、替代法、补偿法,以及对称观测法4种减小测量加过误差的测量方法。希望有关人员加以借鉴和思考,对测量误差和测量方法进行更多的研究,探讨出行之有效的方案来减小测量过程中出现的测量误差,从而提高整个测量的精确度,保障测量工作的科学性和先进性,进一步促进相关测量行业的不断健康发展。     

Vibrational analysis of angle measurement comparator

The comparators of angle measurement are designed for measurement of angle gauges (limbs) and angular movements (turning) for calibration measurement errors of measuring systems. The vibration isolation issue for angle comparators is particularly relevant. Vibration analysis became essential for angle comparators operating in dynamic mode and used for precise angular measurements. In this paper, an analysis of wavelet intensity distributions of angle comparators is carried out by applying the theory of covariance functions. Data from measurements of vibrational signals at fixed points were acquired in the form of data arrays (matrices). Estimates of covariance functions between the arrays of data and the estimates of covariance functions of single arrays were calculated upon changing the quantization interval on the time scale. For signal processing, MATLAB 7 software was applied.     

Error analysis of tissue resistivity measurement

We identified the error sources in a system for measuring tissue resistivity at eight frequencies from 1 Hz to 1 MHz using the four-terminal method. We expressed the measured resistivity with an analytical formula containing all error terms. We conducted practical error measurements with in-vivo and bench-top experiments. We averaged errors at all frequencies for all measurements. The standard deviations of error of the quantization error of the 8-bit digital oscilloscope with voltage averaging, the nonideality of the circuit, the in-vivo motion artifact and electrical interference combined to yield an error of +/- 1.19%. The dimension error in measuring the syringe tube for measuring the reference saline resistivity added +/- 1.32% error. The estimation of the working probe constant by interpolating a set of probe constants measured in reference saline solutions added +/- 0.48% error. The difference in the current magnitudes used during the probe calibration and that during the tissue resistivity measurement caused +/- 0.14% error. Variation of the electrode spacing, alignment, and electrode surface property due to the insertion of electrodes into the tissue caused +/- 0.61% error. We combined the above errors to yield an overall standard deviation error of the measured tissue resistivity of +/- 1.96%.     

电力计量系统防分流窃电技术的分析

本文对电力计量系统及常见的窃电方法进行简单介绍,并对电力计量系统防分流窃电技术进行具体分析.     

Broadband channel measurement and analysis

1 Introduction A complete understanding of propagation characteristics of wireless channel is the key for designing a mobile wireless communication system as the outcomes of various researches on wireless channel are regarded as the basis of mobile wirele…