共查询到19条相似文献,搜索用时 187 毫秒
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计量校准是量值传递和量值溯源最重要的手段,而测量不确定度是评价计量校准质量的重要指标。文章介绍了测量不确定度在国内外发展经历,对其概念进行了阐述,针对时间频率计量实例说明了测量不确定度评定中评定步骤、建模方法、合成标准不确定度计算等关键问题。 相似文献
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为了确保植物叶片参数测量仪的检测数据准确可靠,结合其工作原理,依据校准方法,对厚度参数和温度参数测量结果进行科学、合理的不确定度评定分析,验证其测量结果能够满足量值溯源要求,对计量检定机构开展该类仪器的校准工作有一定的指导意义。 相似文献
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本文利用调幅正弦波的高稳定性及其波形中又存在功率最高点的特点,提出了一种基于正弦波调幅信号对峰值功率计线性度进行校准的新方法。该方法只需使用信号发生器和测量接收机就能够实现对峰值功率计线性度的校准,与标准峰值功率计测量结果误差不超过±0.1dB,并可通过调制度溯源到连续波功率,解决了峰值功率量值溯源的问题。是一种简单易行,准确度高的方法。 相似文献
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仪表着陆信号发生器是仪表着陆系统机载设备的专用检测设备,目前国内还没有公开发布的关于仪表着陆信号发生器的国家或行业范围内的检定/校准技术标准。本文通过对仪表着陆系统原理进行剖析,从仪表着陆信号发生器工作特点入手,对航向信标、下滑信标、指点信标等信号特点进行分析,给出了计量特性,并基于频谱分析仪直接测量法给出了各项计量特性的校准方法,同时对频谱分析仪引入的测量不确定度进行了分析,用GUM法评定了扩展不确定度。结果表明,给出的校准方法可满足仪表着陆信号发生器关键参数的校准需求,使用频谱分析仪校准符合仪表着陆信号发生器各计量特性的量值溯源要求。 相似文献
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A mathematical model is presented for predicting the flash point of miscible mixtures. This model is reducible and adequate for some specified systems as proposed previously. Except for multiple aqueous-organic solutions, the predictive capability of the reduced form for other miscible mixtures, including binary aqueous-organic solutions and flammables-only analogues, has been verified previously. The model was validated using the ternary aqueous-organic solutions, water+methanol+ethanol/isopropanol. The results of the study confirm that the model predicts the flash points of these solutions by utilizing the flash points of the individual components. Further, if the binary interaction parameters for a ternary aqueous-organic solution are not accessible, a model based upon the binary interaction parameters of the binary solutions may provide a very acceptable means of predicting the flash point for such a ternary solution through comparison of the predicted and experimental data, as demonstrated in this study. 相似文献
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A fast-pulse oscilloscope calibration system 总被引:8,自引:0,他引:8
Deyst J.P. Paulter N.G. Jr. Daboczi T. Stenbakken G.N. Souders T.M. 《IEEE transactions on instrumentation and measurement》1998,47(5):1037-1041
A system is described for calibrating high-bandwidth oscilloscopes using pulse signals. The fast-pulse oscilloscope calibration system (FPOCS) is to be used to determine the step response parameters for digitizing oscilloscopes having bandwidths of ~20 GHz. The system can provide measurement traceability to standards maintained at the U.S. National Institute of Standards and Technology (NIST). It comprises fast electrical step generation hardware, a personal computer (PC) and software, and a reference waveform, i.e., a data file containing an estimate of the step generator output signal. The reference waveform is produced by prior measurement by NIST of the step generator output signal (calibration step signal). When the FPOCS is in use, the calibration step signal is applied to the device under test, which is an oscilloscope sampling channel. The measured step waveform is corrected for timebase errors, then the reference waveform is deconvolved from it. The results are impulse, step, and frequency response estimates, and their associated parameters (e.g., transition duration, transition amplitude, -3 dB bandwidth) and uncertainties. The system and its components are described, and preliminary test results are presented 相似文献
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白光干涉测量系统(white-light interference system, WLIS)广泛用于微纳米表面形貌的精密测量,其测量不确定度评定是研究白光干涉测量系统计量特性的一项重要工作。基于微纳米线间隔和台阶,建立了WLIS测量表面形貌时的测量模型,明确了测量不确定度来源;以5000nm的线间隔和180nm的台阶高度为例,利用WLIS进行了测量,并分析WLIS的测量重复性、光学组件特性、传感器特性、运动模块性能、测试方法及环境等因素产生的不确定度分量,最终评定该WLIS测量线间隔和台阶高度的合成测量不确定度分别为21nm和0.4nm。对WLIS的不确定度评定确保了其测量结果的准确性、溯源性,并提出了提高系统整体计量特性的途径。 相似文献
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结构物理参数识别的多尺度参数卡尔曼滤波方法 总被引:1,自引:0,他引:1
经过正交小波变换后,低尺度上测量信号的信噪比提高。应用小波变换将结构的激励信号和响应信号分解到不同尺度上,得到不同尺度上结构的状态方程和测量方程,结合动力学系统辨识的参数卡尔曼滤波方法,提出了结构物理参数的多尺度参数卡尔曼滤波辨识方法。理论分析和数值算例表明:在多尺度上对结构参数进行辨识比在单一尺度上辨识能获得更高的精度。 相似文献
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Stripping voltammetry analysis using a hemispheroidal mercury microelectrode is assessed as a possible candidate "primary method" for amount of substance measurement. It has been shown that this measurement methodology can be described completely by a set of measurement equations. Novel proposals are made to improve the accuracy and traceability of the quantification process by measuring the limiting deposition current over an optimum time instead of employing an analyte stripping step. The range of application and the limitations of the technique are discussed, and the requirement for underpinning traceability from electrical standards is shown. It is concluded that the lack of amount-independent diffusion coefficient data limits the status of the technique to a high-accuracy "definitive method" at present 相似文献