漫话量值溯源

检测在保障社会进步和经济发展中发挥着不可替代的重要作用,社会的方方面面时刻都离不开检测。凡涉及检测,无一例外地存在一个测量准确性问题,解决它的根本做法就是证明溯源性。一、什么是量值溯源测量的目的是确定量值,量值又由一个数值乘以其计量单位构成。为了确保在不同时间、不同地点,不     

产品质检机构应高度重视量值的溯源性

近年来，我国许多产品质量检验机构（以下简称实验室）按照计量认证／审查认可（验收）评审准则或ISO／IEC17025实验室认可准则，建立和运行质量管理体系。并通过认证认可。这些活动帮助实验室完善了质量管理体系，提高了工作质萤和信誉，为实验室长远发展奠定了坚实的基础。但也有不少实验室虽然通过计量认证／审查认可（验收）或ISO／IEC17025实验室认可。而在实验室量值的溯源性上仍存在不足．亟须改进和完善。     

浅谈量值传递和量值溯源的实施

本文阐释了量值传递和量值溯源的关系,介绍了我国的量值传递和量值溯源的方式,并对量值传递和量值溯源体系提出了建议。     

关于实验室量值溯源工作的探讨

实施量值溯源是计量工作的主要任务之一,涉及计量器具、法制管理的各个环节。量值溯源也是保证量值准确、可靠、一致的基本手段和基本途径。本文从量值溯源的概念、量值溯源的要求、量值溯源的途径和量值溯源的实施等几个方面对实验室的量值溯源工作进行论述。     

有关量值溯源和SI的相关知识介绍

ISO/IEC 17025∶2005要求“用于检测/校准的所有设备,包括对检测、校准和抽样结果的准确性和有效性有显著影响的辅助测量设备,在投入使用前必须进行校准”。且“实验室所进行的校准和测量应溯源到国际单位制(SI)”。如此要求是为了确保检测结果的准确、统一。1量、数值和单位所谓测量是“以确定量值为目的的操作”,强调测量是操作,是一个过程,最终要给出测量结果,目的在于确定量值。所谓操作就是用实验方法将被测未知量和已知标准量进行比较,以求得被测未知量的数值。未知量和标准量中的“量”是“现象、物体或物质的可定性区别和定量确…     

ISO／IEC17025与实验室测量溯源性

一、引言近年来 ,国际上实验室认可活动非常活跃。这促进了各国和各地区的认可机构间相互认可协议的签署 ,为最终消除国际贸易中由于检测和校准数据不信任所造成的贸易技术壁垒奠定了很好的基础。而我国实验室认可工作亦得到国际首肯。继 1 999年 1 2月在印度新德里获得亚太地区实验室认可机构的承认后 ,2 0 0 0年 1 1月在美国华盛顿 ,中国实验室国家认可委员会与国际实验室认可合作组织的实验室认可机构签署了相互承认协议。该协议由来自欧洲、南美洲、南非和亚太地区的 36个实验室认可机构共同签署。为我国实验室出具校准和检测数据得到国…     

关于检测／校准结果“意见和解释”的探讨

新发布的ＩＳＯ/ＩＥＣ 1 70 2 5-1 999《检测和校准实验室能力的通用要求》标准中 ,多处提到了对检测 /校准结果的意见和解释。这一新的要求 ,在使用中有的将“意见和解释”与“结论”相混淆 ;有的对意见和解释监控不到位 ,带有一定随意性 ;有的不能准确把握意见和解释的作用与应用。本文将对检测 /校准结果的意见和解释的提出、应用、要求及注意事项等作一探讨与阐述 ,以便对该标准中提出的“意见和解释”有一个准确而完整地理解与应用。1　意见和解释的提出与回顾1 1　对ＩＳＯ/ＩＥＣ1 70 2 5-1 999制定过程的简要回顾在建议的基础上 ,…     

加强专用测试设备的校准和管理,健全量值溯源渠道

本文阐述了企业加强专用测试设备校准和管理，健全量值溯源渠道的必要性，分析了专用测试设备管理中存在的问题及解决的方法和途径。     

对质检机构量值溯源性的思考

本文主要介绍实验室计量仪器在溯源性方面存在的问题及改进措施.     

实验室仪器设备量值溯源的总体要求

量值溯源性是通过一条具有规定不确定度的不间断的比较链,使测量结果或标准的值能够与规定的参考标准,通常是国家的或国际标准联系起来的一种特性。溯源的目的就是强调所有测量结果或标准的量值都能最终溯源到国家基准或国际计量基准,即SI单位的复现值。     

我国的检验检测市场距离中介检验检测市场还有多远

本文分析了我国检验检测市场的现状,指出了政府实验室和中介（商业）实验室的定位和区别,并指出,在目前乃至今后相当长的时间内,我国检验检测市场以政府检验检测市场为主导地位,中介检验检测市场的最终形成要与我国经济发展和政府机构改革、政府职能的转变形势相适应,还需要相当的历史阶段才能完成.     

Far infrared emission and portable testing device of fine powders

In order for industrial and mining enterprises to fast detect the quality of fine mineral powders with far infrared emission, a simple testing model was set up according to the relationship between the emission intensity of powders and their surface temperature. The corresponding testing device was designed and assembled into three parts containing Constant Temperature Heating Part, Temperature Measuring Part and Sample Loading Part. By using the tourmaline mineral powders with far infrared emission as the research object and combining Fourier transform infrared spectroscopy, the calibration for the testing device was carried out. The results showed that the far infrared emission intensity of the tourmaline powders with different mining area and particle size could be judged. The testing results exhibited correct values when compared with those from FTIR measurements.     

How does it change safety margins if overtaking is prohibited: A pilot study

Overtaking was temporarily prohibited on a 1.2km long stretch of two-lane road and the time headway for every car, passing the site in a certain direction, was measured at two points between which the prohibition sign was posted. Additionally, the lateral position of every car was recorded. Due to the prohibition, some favorable effects on safety margins were found. When passing the prohibition sign the drivers following another car very closely increased their following distance; no such change was found in the control condition. Furthermore, when overtaking prohibited, the closely following drivers reserved a bit greater safety margin with respect to the oncoming vehicles. The results suggest that waiting for an opportunity of overtaking increases the accident risk by inducing very short following distances and driving near the center line. This implies that the total accident loss due to overtaking is not wholly included in the category “overtaking acidents” but, in fact, a part of rear-end accidents should be counted on overtaking, too. This should be taken into account when estimating the pay-off of overtaking on two-lane roads.     

Weight reduction — is it a valid concept?

Much has been made in recent years of the use of lightweight materials to reduce the fuel consumption of automobiles. Dr. Howard Hornfeld, a plastics consultant with Consultex SA questions whether this is now a cost-effective philosophy.     

Crack closure - is it just a surface phenomenon?

The fatigue crack closure response in the plane strain regions of a BS4360 50B steel specimen is evaluated. Compliance measurements using a new type of closure gauge, crack-mouth clip gauge and back face strain gauge show that the fatigue crack is closed for a significant portion (20%) of the load cycle. A sectioning technique is used to confirm that the fatigue crack is closed along the whole crack front, at zero load.     

世界烟标之最

世界上最早的烟标是1880年奥匈帝国的烟草制造商为扩大商品影响,在卷烟制品上贴上一个标志,制造了"尼尔"牌卷烟,为世界各国卷烟厂所效仿.     

不合格建材如何流入市场

6月20日,国家质检总局新颁布了由国家标准物质研究中心、国家地质实验测试中心等单位新研制的42种国家一级标准物质和43种国家二级标准物质。