逆扩散型氦质谱检漏仪的研究

一、常规型质谱检漏仪的发展真空检漏技术中,唯有氦质谱检漏仪灵敏度最高。广泛采用,发展较快亦较成熟。早在四十年代其检漏灵敏度为10~(-8)托·升/秒,到五十年代末达10~(-13)～10~(-14)托·升/秒。国内在六十年代以来分别研制的氦质谱检漏仪以及国外绝大部分质谱检漏仪新产品均属常规形式(见附表1、表2)。被检漏件与节流阀相连,由辅助机械泵完成粗抽。检漏时节流阀徐徐打开,调至质谱室允许的工作压强,质谱室真空由扩散泵抽气。为提高系统的真空度和质谱室少受沾污,一般加有液氮冷阱,前级有机械真空泵以及必要的一些辅助的旁路或     

航天器氦质谱真空容器总漏率检测的灵敏度及可信度探讨

依据航天器氦质谱真空容器总漏率检测原理,讨论了检漏仪和真空容器直接相连、同真空容器主真空泵并联、在前级泵和主真空泵间等连接方式,逐项研究了总漏率测试的最小可检漏率、反应时间,分析各种连接方式的应用特点,认为对大型航天器氦质谱真空容器检漏系统,检漏仪连接在前级泵和主泵之间可得到较好的灵敏度和反应时间.通过测量不确定度的分析与评定,确定一般航天器氦质谱真空容器总漏率检测的相对标准不确定度小于10％.     

高分辨四极质谱计在HL-2A装置上的应用

将具有分辨氦(He)和氘(D2)能力的高分辨四极质谱计安装到HL-2A托卡马克装置上,同时送入氦气和氘气,得到了质谱计可分辨的最小He+/D2+峰值比.分别对真空室在辉光放电清洗前后、不同等离子体放电次数的氢同位素和氦进行测量,观察到四种工况下质谱峰m/q=4的主要成分为D2+,He+只在辉光放电清洗中作为工作气体引入.向真空室送入氘气后,比较了由分子泵和低温泵抽气的质谱情况.分压强的测量结果表明低温泵对氘气的抽速大于分子泵约18％.实验结果初步验证了高分辨四极质谱计应用于托卡马克装置可靠真空检漏和残余气体成分精确分析的可行性,并为托卡马克装置抽气泵的选型提供了依据.     

氦质谱检漏仪性能诸元关系的研究

本文根据顺流式氦质谱检漏仪和逆流式氦质谱检漏仪真空系统的结构配置特点,分别推导出这两类检漏灵敏度、最高入口工作压强、抽气时间、最小可检漏率、最大可检漏率、响应时间和清除时间等特性的普适性计算公式。这些公式能够解释有关的实验结果,有助于分子泵逆流检漏仪的研制开发。     

ZhP－30型氦质谱检漏仪的设计特点和性能

ＺｈＰ－３０型氦质谱检漏仪采用涡轮分子泵真空系统，以逆扩散方式检漏；只有一个操作手柄的组合阀可完成预抽、检漏和放气的全部功能；取代传统的冷规，用总离子流测量质谱室压强并提供对灯丝的过压保护．本文给出分子泵作检漏用的各项特性。仪器最小可检漏率＜５×１０（－１１）Ｐａ·ｍ３／ｓ．     

关于氦质谱检漏仪的反应时间的两种测量方法

本文对氦质谱检漏仪的反应时间的两种测量方法进行了讨论,指出其中一种方法是错误的。 反应时间和清除时间是氦质谱检漏仪的重要参数之一,通常规定反应时间和清除时间不大于3秒。对仪器经常进行灵敏度校准和反应时间与清除时间的测量是检查仪器是否正常工作的手段之一。就是在检漏工作进行过程中,对于检漏技术人员来说也应该知道在连接了被检容器和辅助真空系统之后,整个检漏系统(包括检漏仪、被检件、辅助真空系统)的检漏灵敏度多大?反应时间与清除时间多长?这些决定了能够检示出多大漏孔和应该以怎样的速度进行检漏的问题。 下面只谈一下…     

第七讲：真空检漏

第七讲：真空检漏关奎之（东北大学）２．氦质谱检漏仪法（接１９９８年第１期第５０页）利用氦质谱检漏仪进行检漏的方法有：喷吹法、氦罩法、检漏盒法、吸枪法、充压法、背压法、累积法、选择性抽气法、检漏台法、逆流检漏法和标准漏孔比较法。各种方法的设备、步骤及漏...     

涡轮分子泵逆检流漏技术研究

一、逆流检漏方法的特点在通常的氦质谱检漏法中,被检件接在检漏仪的高真空侧,被检件通过节流阀与检漏仪的质谱室相连,如图1所示。氦气通过漏孔进入被检件并被抽入质谱室,其中一部分被主泵抽走,另一部分在氦质谱室中建立起氦分压,由此形成了     

空调器生产线的氦质谱检漏技术

氦质谱检漏技术在空调器生产中已得到了应用，产生了明显的经济效益。对于生产线的空调器整机检漏采用了加压吸枪法。研制的检漏设备分三部分：充氦系统、氦质谱检漏仪和氦气回收系统，回收效率可达９０％以上。设计了一套二器（冷凝器和蒸发器）氦质谱检漏设备。这套设备可对两器进行总检，其检漏速度达５０ｓ／台，灵敏度达１０－９Ｐａ·ｍ３／ｓ。     

大型金属超高真空系统检漏的特点和方法

阐述大型系统超高真空获得及运行过程检漏工作的几个特点。对结构复杂的真空室，如何使用分子筛吸附泵与氦质谱检漏仪相结合提高检漏灵敏度，极大限度地找出泄漏的位置。还指出大型金属超高真空系统运行过程如何根据溅射离子泵离子流的数据，判断真空系统漏气及寻找漏点的方法。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

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.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

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.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

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