冲击式气扳机拧紧扭矩测量不确定度研究

该文主要研究冲击式气扳机拧紧扭矩测量结果的不确定度评定,按照标准JB/T8411-2006《冲击式气扳机》和GB/T5621-2008《凿岩机械与气动工具性能试验方法》要求,结合新型冲击累积扭矩测量设备,对动态冲击扭矩测量结果进行不确定度评定,验证了该设备扭矩测量的精度,同时为冲击式气扳机扭矩测量结果不确定度评定提供参考。     

播种机排种量测量结果不确定度评定和分析

依据DG/T 007-2019《播种机》、GB/T 9478-2005《谷物条播机试验方法》与GB/T 27418-2017《测量不确定度评定和表示》对播种机排种量测量结果的不确定度进行评定,推导出适用于播种机排种量测量结果不确定度评定公式,分析了影响测量结果不确定度的因素,提出了适用于播种机排量测量结果不确定度分析的方法。     

0.5级力传感器示值误差测量结果的不确定度评定

采用杠杆式测力机标准装置依据JJG 391-2009《力传感器检定规程》测量0.5级力传感器并参考JJF 1059.1-2012《测量不确定度评定与表示》对其测量结果不确定度进行评定。文章探讨了检定力传感器测量结果的不确定度来源,评定过程和方法。     

拉伸试验测量不确定度分析

力学性能指标是评定材料和零部件的重要指标,拉伸试验是测量力学性能的重要一环,检测结果是否有效可靠尤为关键,为了验证我公司拉伸试验检测过程和检测数据的有效性和可靠性,根据GUM即国际标准《测量不确定度第3部分:测量不确定度指南》和JJF1059.1-2012《测量不确定度评定与表示》标准规定的方法,选取Q235热轧钢板制成试样做拉伸试验,进行不确定度分析评定,结果表明,拉伸试验不确定度的水平与GB/T228.1-2010《金属材料拉伸试验第1部分:室温试验方法》标准附录预测水平相当,我公司实验室拉伸试验过程受控正常,检测数据有效可靠。     

起重机主梁上拱度测量不确定度的评定

文中介绍了依据国标GB／T14405—93《通用桥式起重机》检测标准,按JJF1059—1999《测量不确定度评定与表示》对起重机特种设备主梁上拱度测量结果进行不确定度的评定方法。     

原子吸收法测定水样中铅含量的测量不确定度评定

根据GB/T7475-1987,使用原子吸收光度法测定水质样品中铅的含量,按照JJF1059-1999《测量不确定度评定与表示》的要求对测定结果进行不确定度评定。分析测定过程中不确定度来源,计算各不确定度分量,求出合成不确定度和扩展不确定度,给出测定结果报告。当样品铅含量为1.31 mg/L时,测量结果的扩展不确定度为0.05 mg/L,k=2。     

压缩空气中悬浮油含量的测量不确定度评定

以GB/T 13277.2-2015《压缩空气第2部分:悬浮油含量测量方法》中B2方法为依据,测量了压缩空气中的悬浮油含量,并按照JJF 1059.1-2012《测量不确定度评定与表示》,评定了测量结果的不确定度。首先确定了不确定度的来源,并对各分量进行了分析和计算,最终结果表明,取样过程的流量测量和从高效玻璃纤维膜片中萃取油份时引起的不确定度最大。     

300kg数字指示秤示值误差测量结果的不确定度评定

根据JJF 1059-1999《测量不确定度评定与表示》的要求和JJG 539-1997《数字指示秤检定规程》的规定,对现今社会上使用量大、易对检测结果发生混淆的300kg数字指示秤示值误差进行不确定度评定,根据测量结果的重复性、偏载示值误差、电源电压变化对检测结果的影响和标准砝码引入的不确定度等方面进行综合的分析,进行不确定度评定。     

测量不确定度在金相检测分析中的应用探讨

金相检测分析是判定产品内在质量的一种实验技术,检测分析结果的准确可靠程度是评价试验质量的重要指标,反应了实验结果的可信度,是实验室检验技术的一项重要体现。如何判断金相检测分析结果的准确程度,我们可以运用“测量不确定度评定”标准进行分析评定。根据GUM即国际标准《测量不确定度第3部分:测量不确定度指南》和JJF1059.1-2012《测量不确定度评定与表示》标准规定的方法,借助于AXio observer光学金相显微镜进行金相检测分析,根据金相检测结果不确定度产生的来源,引入分析各不确定度分量原因数据,进而评定测量不确定度。     

机电式交流电能表测量结果不确定度评定分析

依据JJG307-2006《机电式交流电能表》检定规程,对2.0级机电式三相四线交流有功电能表的平衡负载点示值误差进行测量,并分析评定测量结果不确定度,得到测量结果不确定度评定报告。     

高效液相色谱法测定牛初乳粉中IgG含量的不确定度评估

建立高效液相色谱法测定牛乳乳粉中IgG含量的不确定度评估方法,依据GB/T5009.194-2003《保健食品中免疫球蛋白IgG的测定》和JJF1059-1999《测定不确定度的评定与表示》,建立不确定度的数学模型,分析IgG含量测定的不确定度,为检验工作的质量控制提供帮助。     

Determining environmental noise measurement uncertainty in the context of the Italian legislative framework

This paper aims to demonstrate the importance of uncertainties in the measurement of environmental noise in the context of Italian legislation on noise pollution focusing the attention on the variability of the measurand as a source of uncertainty and offering a proposal for the evaluation of uncertainty for traffic noise measurement. In particular, drawing on a real traffic noise dataset, firstly outliers are eliminated from the actual noise measurements using an outlier detection algorithm based on K-neighbors distance and then uncertainty range is estimated with the bootstrap-t method. Since the original sequence was Gaussian, this range was compared with the confidence interval of the mean ± standard deviation interval and two intervals were almost coincident.     

M1等级砝码组折算质量测量结果的不确定度评定

根据本所的计量标准装置,结合JJG99-2006《砝码检定规程》要求,以20kg和500kg砝码为例详细介绍了M1级砝码组折算质量测量结果的不确定度评定的具体方法和步骤。     

数字汽车衡测量结果的不确定度评定

本文对数字汽车衡测量结果的不确定度进行评定,从建立数学模型着手,确定不确定度的来源,依据JJF 1059-1999《测量不确定度评定与表示》进行分析、计算,得出评定结果。     

Effect of multiplicative noise on least-squares parameter estimation with applications to the atomic force microscope

Measurement of the power spectral density of (stochastic) Brownian fluctuations of micro- and nano-devices is used frequently to gain insight into their mechanistic properties. Noise is always present in these measurements and can directly influence any parameter estimation obtained through a least-squares analysis. Importantly, measurements of the spectral density of stationary random signals, such as Brownian motion, inherently contain multiplicative noise. In this article, we theoretically analyze the impact of multiplicative noise on fit parameters extracted using a least-squares analysis. A general analysis is presented that is valid for any fit function with any number of fit parameters. This yields closed-form expressions for the expected value and variance in the fit parameters and provides a rigorous theoretical framework for a priori determination of the effect of measurement uncertainty. The theory is demonstrated and validated through Monte Carlo simulation of synthetic data and by comparison to power spectral density measurements of the Brownian fluctuations of an atomic force microscope cantilever - analytical formulas for the uncertainty in the fitted resonant frequency and quality factor are presented. The results of this study demonstrate that precise measurements of fit parameters in the presence of noise are inherently problematic - individual measurements of the power spectral density are capable of yielding fit parameters that are many standard deviations away from the mean, with finite probability. This is of direct relevance to a host of applications in measurement science, including those connected with the atomic force microscope.     

如何用虚拟仪器测量灰气比

灰气比是衡量气力输送系统效率的重要指标,但灰气比的测量一直是难点,特别是气量的精确测量更难。主要是因为气体品质受温度、压力、时间影响较大,是个时变的量．传统仪器几乎无法做到精确测量和记录。采用虚拟仪器进行测量,不但成本低而且精确度高：在沙角电厂的实测中,通过记录各电场的瞬时流量曲线,找出了如何正确调整各电场发送逻辑,改善了用气量,解决了原气源不足的难题．     

Design and evaluation of electrostatic sensors for the measurement of velocity of pneumatically conveyed solids

Electrostatic sensing technology in combination with correlation signal processing offers a promising solution to the on-line continuous measurement of velocity of particulate solids in pneumatic pipelines. This paper describes the fundamental mechanism of the electrostatic sensing and identifies the important aspects of the design of constituent elements of the sensor including electrodes, amplifiers and sensing heads. Experimental evaluation of a prototype commercial product called V-TESS 500 was conducted on 36 mm bore vertical and horizontal sections of a pneumatic conveyor circulating corn-flour and pulverised coal over a velocity range of 6 to 45 m/s for mass concentration of particles between 0.014 and 5.7 kg/m³. The performance of the instrument was quantified in terms of repeatability, linearity and response time. The uncertainty of the system was studied by comparing the measured solids velocity to the superficial air velocity in the pipeline. Effects of particles' accretion on the inner surface of the pipe wall on the measurement are also included. Results obtained demonstrate that the system is capable of providing solids velocity measurements with repeatability better than ±2% and response time less than 2.5 s.     

乳粉中汞含量测定的不确定度评定

测量不确定度定义为表征合理地赋予被测量之值的分散性[1]。在ISO/IEC17025-1999中要求检测实验室具有评价不确定度的程序,能够对测量项目的不确定度做出正确的评估,满足客户及监测工作的要求。在这种情况下,实验室应努力找出不确定的所有分量且做出合理评定,确保检验结果不确定度已知度符合要求。作者依据测量不确定度的评定原则,通过实例,简要地阐述了原子荧光法测定乳粉中汞的不确定度评定方法,对检测领域测量不确定度的评定具有借鉴意义。     

浊度计仪器示值误差测量结果不确定度评定

依据JJG880-2006浊度计检定规程,介绍了浊度计示值误差测量结果不确定度的评定方法,对配制标准溶液所使用的玻璃量器所引入的不确定度分量进行了分析和评定。