浅谈管道工程焊接过程中的质量控制

焊接是管道施工中的特殊过程。通过对长输管道安装过程中的焊接及无损检测质量控制的分析,阐明了管道工程质量控制过程中需要加强焊接层的质量控制,完善焊接过程中和无损检测过程的质量控制,对长输管道工程的施工具有理论及实践借鉴意义。     

浅谈实验室计量检测质量控制

在实验室进行的各项活动中,计量检测过程和计量检测结果是影响质量控制的两大主要因素,质量管理就是通过控制与这些相关的因素来实现。按照过程质量控制因素和结果质量控制因素的分类,对在计量检测中影响质量控制的因素提出改进措施,以期提高计量检测的能力和服务水平,提高实验室的整体能力。指出检测过程控制一般从设施环境、测量设备、检测人员、检定和校准及检测方法的选择等不同途径进行控制,检测结果的质量控制主要包括原始记录、证书报告和实验室能力验证对质量控制的影响等。     

基于累积和控制图的自适应沸腾状态检测

分析了液体加热过程特性和噪声特征,将基于升温速率变点的沸腾状态检测转化为白噪声干扰下单边均值变点的在线检测问题。采用累积和控制图进行变点检测,基于积分方程法讨论了控制图参数优化方法。结合加热过程参数的在线估计,构成自适应变点检测方法,对不同加热过程,能够根据过程特点实时更新控制图参数,在实际应用中取得了良好的检测效果。     

信噪比在分析残差控制图检测能力中的应用

应用信噪比与平均运行长度2种方法,分析了自相关过程由时间序列模型AR(1)描述时,残差控制图对过程均值变化的检测能力.结果表明,信噪比是控制图的检测能力的一个良好指标,在合理参数0.1≤λ≤1-φ范围内,残差EWMA控制图对过程均值小偏移较灵敏,对过程均值大偏移的检测能力略差于残差Shewhart控制图.     

质量控制图在实验室质量管理中的应用

质量控制图是实验室开展质量控制工作的一种重要工具,便于实验室有效识别检测过程中出现的系统性变异,及时采取措施,使检测过程保持稳定。     

控制图在食品检验机构中应用

本文阐述了控制图的原理和绘制方法,利用食品中蛋白质检测的-X-R图来说明控制图在食品检测实验室中的应用,利用控制图可以判断系统效应和随机效应对食品检测过程的影响是否增大,与能力验证等其他质量控制手段相比,控制图具有方便易于操作的特点,食品检验机构可以及时发现检测过程中各阶段存在的波动情况并加以控制。     

产品质量与计量检测

一、产品质量的形成过程离不开计量检测 产品质量是在从原材料、辅料通过生产过程转化成最终的产品所形成的。产品生产过程是由一系列生产工艺所形成的,并由一系列生产工艺控制过程组成。产品质量水平取决工艺水平和工艺过程参数的控制水平。而工艺过程参数,如冶金、石油、化工企业产品生产过程中的温度、压力、流量、液位必须通过生产设备上安装的各种温度计、压力计、流量计和液位计等计量检测设备所检测和指示的计量检测数据来判定工艺过程是否处于有效的控制状态。     

化学实验室内部质量控制的技术方法

<正>0引言为了保证检测数据的准确可靠,有必要对检测过程及其各阶段中可能影响报告质量的各个因素加以确定,并采取相应的措施对这些因素进行管理和控制。确保检测环节的各个过程处于受控状态,以保证最终检测报告的质量。实验室的内部质量控制主要是指应用统计的技术方法对检测系统进行的过程控制。在实验室认可中,强调各个过程应处于受控状态,特别是关键过程。从权威性的方面来说,实验室外部质量控制无疑是远优于实验室内部质量控制的。但是,实验室     

实验室的内部质量控制

<正>0引言实验室质量控制是对于检测活动相关的全部过程的控制。按照不同的方法可以将实验室质量控制进行分类,包括有其他实验室参与的实验室外部质量控制和仅由本实验室自己组织实施的实验室内部质量控制两部分。还可分为环境质量控制、设备质量控制、样品质量控制、方法质量控制,以及结果质量控制(样品检测过程质量控制)等。本文仅对实验室内部质量控制进行研究,不涉及实验室外部质量控制。在实际检测工作中,由于影响实验室检测结果     

综述工程质量检测监理方法

工程质量检测是工程质量控制的重要组成部分,而质量控制又是现阶段工程监理的核心。监理工程师要搞好房屋建筑工程施工质量控制,必须在监理过程中了解工程质量检测的内容,掌握工程质量检测的监理方法,做好工程质量检测监理工作。     

Gender differences in publication productivity in psychology in India

An analysis of gender differences in psychology in India provides quantitative and qualitative assessment of R&D output contributed by psychologists with the indication of the trend of growth, skewness, relatedness, co-authorship pattern of productivity.     

Metrology in Chemistry in Germany

The system for Metrology in Chemistry in Germany is described. At the national standards level, a network of high-level chemistry institutes coordinated by the national metrology institute, PTB, provides the primary references for chemical measurements. A dissemination mechanism employs chemical calibration laboratories accredited within the framework of the German Calibration Service (DKD). They act as “multipliers” between the national standards level and the user level by providing the user with calibration means which are traceable to the SI via national standards. Traceability structures in clinical chemistry, electrochemistry, elemental analysis and gas analysis are described     

Natural radioactivity in drinking water in private wells in Finland

Natural radioactivity in drinking water was determined in population-based random study of 472 private wells. The mean concentrations of (222)Rn, (226)Ra, (234)U, (238)U, (210)Pb and (210)Po in drilled wells were 460, 0.05, 0.35, 0.26, 0.04 and 0.05 Bq l(-1), and in wells dug in the soil were 50, 0.016, 0.02, 0.015, 0.013 and 0.007 Bq l(-1), respectively. Approximately 10% of the drilled wells exceeded a radon concentration of 1000 Bq l(-1) and 18% a uranium concentration of 15 microg l(-1). The mean annual effective dose from natural radionuclides for a drilled well user was 0.4 mSv and 0.05 mSv for a user of a well dug in the soil. The effective dose arising from (222)Rn was 75% of the total of all natural radionuclides for drilled well users. As regards long-lived radionuclides, (210)Po and (210)Pb caused the largest portion of the effective dose. The dose arising from (238)U, (234)U and (226)Ra was only 8% of the total of all natural radionuclides.     

Natural radioactivity in drinking water in private wells in Finland

Radiation Protection Dosimetry     

Radioactivity in building materials in Iraq

Activity concentrations of (226)Ra, (232)Th and (40)K in 45 samples of different building materials used in Iraq were measured using gamma-spectroscopy system based on high-purity germanium detector with an efficiency of 40 %. Radium equivalent activity, air-absorbed dose rate, annual effective dose, external and internal hazard indices and alpha index due to radon inhalation originating from building materials were measured to assess the potential radiological hazard associated with these building materials. The activity concentrations of the natural radionuclides (226)Ra, (232)Th and 40K were found to range from below detection limit (BDL) to 223.7 ± 9, BDL to 93.0 ± 3 and BDL to 343.1 ± 12, respectively. Values of average radium equivalent activity, air-absorbed dose rate, indoor and outdoor annual effective doses, external and internal hazard indices and alpha index ranged from 6.5 to 124.9, 16.2 to 89.5 (nGy h(-1)), 0.08 to 0.44 mSv, 0.02-0.11 mSv, 0.09 to 0.53, 0.13 to 0.69 and 0.03 to 0.62, respectively. These values indicate a low dose. Therefore, the building materials used in the current study are quite safe to be used as building materials.     

Optische in situ Schichtdickenmessung in Bedampfungsanlagen. Optical in situ film thickness monitoring in coating systems

Optical film thickness monitoring is more precise than crystal monitoring. The optical measurement makes use of the fact that the intensity of a monochromatic light beam which is reflected on a film will change periodically with increasing film thickness. The measurement is performed at an exchangeable test glass that is positioned beside the substrates and is therefore coated in the same way as the substrates. The accuracy of cut‐off is achieved by a “fit” of a theoretical curve shape to the measured values. Order filters are used to ensure that, at a certain wavelength, higher deflection orders do not influence the measurement when a monochromator grating is used.