基于液体静力称量法的玻璃浮计校准结果的不确定度分析

液体静力称量法是近年来在密度计校准中所采用的一种高准确度的测量方法,这种方法通过一套完整的基于静力称量法的密度计校准系统来实现。该系统依据阿基米德浮力原理,采用性能稳定的石英环作为参考标准固体密度,以密度稳定、表面张力低的正十三烷为工作标准液体,通过将浮计主体浸入标准液体至于管待测刻线,然后根据空气中和液体中两次浮计称重测量值,最终计算出当前刻线对应密度点的修正值。本文主要以122#(930)基准浮计的校准为例,对影响该基准浮计测量结果的各种因素作了详细的分析,并对各个分量所引入的不确定度进行了数值计算,最终得出该基准浮计对应密度测量范围校准结果的合成标准不确定度及扩展不确定度,进一步验证了该套校准系统的测量有效性和科学性。     

低密度量程浮计式密度计修正值的不确定度评定

低密度量程浮计式密度计的检定是利用液体静力称量法,根据阿基米德原理测量浸在液体中的浮计所受的浮力,从而得到其密度修正值。分析影响结果的各个影响因素,并列出公式计算各个影响因素引入的不确定度,经过计算得出修正值值的合成不确定度。     

基于液体静力称量法的纯水密度测量

分析了液体静力称量法测量密度的原理和体积测量中纯水密度的特性公式,推导了由己知密度的固体标准来测量液体密度的计算公式。利用固体密度基准量传装置,通过静力称量法为固体密度标准硅球赋值,其相对测量不确定度3×10^-6(k=2)。在20℃时利用高精度液体密度测量装置,通过静力称量法将固体标准(硅球)密度传递至纯水密度,与Tanaka模型比对,E_n值为0.059,比对结果等效。实验结果不仅验证了高精度液体密度测量装置,还验证了20℃纯水密度模型的理论值。     

一种新型玻璃浮计检定模式的探讨

本文对采用比较法检定玻璃浮计的不足之处进行了论证.提出了用静力称量法检定玻璃浮计的新方法.该方法的实现将改变目前采用比较法检定玻璃浮计的诸多弊端.是今后玻璃浮计的检定电子化的一个必然方向.     

工作玻璃浮计检定时需要注意的事项

玻璃浮计是用于测量液体密度的基础计量器具,它的正确检定对于密度单位的量值传递与溯源十分重要。笔者从事玻璃浮计检定工作多年,将JJG 42—2011规程内容与实际工作经验结合,从多个方面对工作玻璃浮计检定时需要注意的事项进行了总结,以供同行参考。     

液体表面张力对静力称量法固体密度测量的影响

液体静力称量法是固体密度测量最常用也是测量准确度较高的一种方法。基于阿基米德原理,研究了表面张力对固体密度测量结果的影响。实验选取纯水和纯酒精2种液体作为工作介质,采用一套高准确度液体静力称量装置测量同一固体样品的密度值。实验结果表明,在表面张力小的液体（纯酒精）中固体样品密度测量结果的分散性明显优于在表面张力大的液体（纯水）中固体样品密度测量结果的分散性,为今后提高固体密度测量准确度提供参考方向。     

基于静力称重法的玻璃浮计校准方法研究

采用单晶硅环作为参考标准固体密度,以密度稳定、表面张力低的正十三烷为标准工作液体,选用CCD图像测量系统进行玻璃浮计刻度和液面位置的对准,设计了玻璃浮计校准系统。根据空气中和液体中两次玻璃浮计称重测量值可以计算出当前刻度对应的修正值。对密度测量范围为770~790kg/m³,最小分度为0.2kg/m³的玻璃浮计进行了测量,并与德国国家物理技术研究院进行了双边比对,验证了玻璃浮计校准系统的有效性。     

温度和毛细常数对玻璃浮计示值的影响

本文叙述了使用玻璃浮计测量液体密度时，温度和毛细常数对玻璃浮计示值的影响及其修正方法。     

密度测量数字化的必然趋势

长期以来,几乎所有的物理量的测量都已实现了数字化,然而唯有液体密度的测量仍广泛使用玻璃浮计.由于玻璃浮计存在许多弊端,我们研制开发了SM系列数显密度计(此装置已获国家专利),它代表了密度测量的数字化发展方向.     

温度和毛细常数对玻璃浮计示值的影响

本叙述了使用玻璃浮计测量液体密度时，温度和毛细常数对玻璃浮计示值的影响及其修正方法。     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.     

新闻(英文)

正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to     

Win-Win Cooperation

正The Chinese Premier Li Keqiang's recent trip to the UK has reinforced the China-UK comprehensive strategic partnership;just as the British Prime Minister David Cameron put it,"the relationship is gaining in strength,depth and understanding"after a bucket of business deals being inked worth more than 30 billion US dollars.From the first agreement signing in 2004 to the new agreement of mutual standards recognition and adoption in     

Systematic Approach for Emerging Industry

正A national directory of standards complexes for strategic emerging sectors was recently developed and released jointly by 12governmental departments,namely,SAC,NDRC,MOST,MIIT,MEP,MOA,AQSIQ,State Forest Administration,State Administration of Science and Technology for National Defense,State Oceanic Administration and National Railway Administration.     

Strictest Pollutants Emission Standards

正Four new national standards on air pollutant emission control offi cially issued by the Ministry of Environment Protection(MEP)together with AQSIQ and SAC has been brought into force from July 1,2014.The Emission standard for air pollutants of coal-burning,oil-burning and gasfi red boilers,which is the strictest emission standard historically,will tackle the stubborn pollution problem of boilers and waste incineration in most of China’s regions.     

Instructions to Authors

New Carbon Materials is a bimonthly journal published with the permission of the Ministry of Science and Technology and of the State News and Publication Agency.The journal is sponsored by the Institute of Coal Chemistry,Chinese Academy of Sciences,and is published by Science Press.Aims and Scope     

Progress on Standards Copyright Protection

正Recently,National Copyright Administration of China(NCAC)has rewarded 215 organizations and 179 individuals for their outstanding efforts on investigating standards copyright infringement and piracy in 2013.Hua Jianhua,the Deputy-Director of National Standards Copyright Protection Workgroup Office won a third prize of the national individual award.In 2012,SAC set up the national standards copyright protection working group,and developed policies to crack down standards infringement and piracy behaviors and to strengthen standards copyright protection.