真空计的发展新趋势

结合真空计的发展历史和使用需求,通过对国际上近几年的真空计新产品的分析可知,目前常用真空计具有向小型化、一体化、集成化、系统化和智能化方向发展的趋势。小型化是指真空计的体积越来越小,一体化是指真空计电路部分与规管集成为一体,集成化是指将多只真空计组合为一体,系统化是指将真空度的测量与控制相结合,智能化是指真空计具有自我诊断、自我保护、自动操作和数据处理等综合处理功能。这些趋势是在电子技术和计算机技     

机械制造的智能化技术发展趋势研究

一．机械制造技术的发展在现代制造系统中,数控技术是关键技术,它集微电子、计算机、信息处理、自动检测、自动控制等高新技术于一体,具有高精度、高效率、柔性自动化等特点,对制造业实现柔性自动化、集成化、智能化起着举足轻重的作用。当前,数控技术正在发生根本性变革,由专用型封闭式开环控制模式向通用型开放式实时动态全闭环控制模式发展。在集成化基础上,数控系统实现了超薄型、超小型化;在智能化基础上,综合了计算机、多媒体、模糊控制、神经网络等多学科技术,数控系统实现了高速、高精、高效控制,加工过程中可以自动修正、调节与补偿各项参数,实现了在线诊断和智能化故障处理,在网络化基础上,CAD／CAM与数控系统集成为一体。机床联网,实现了中央集中控制的群控加工。     

MEMS型电容薄膜真空计研究进展

目前常用的电容薄膜真空计体积大、重量重,不能满足深空探测、临近空间探索、战略武器、战地医疗等特殊领域的真空测量需求。基于MEMS技术的电容薄膜真空计,能够使传感器、信号处理和控制电路等结构微型化,突破了传统电容薄膜真空计外形及质量限制,具有体积小、重量轻、功耗低、便于集成化等优点,成为真空测量仪器研究的热点,能更好地满足特殊条件下的真空测量需求。文章对MEMS型电容薄膜真空计的发展现状、技术特点等进行了探讨研究,并对其发展前景提出展望。     

MEMS型电容薄膜真空计的关键技术研究进展北大核心CSCD

近二十年以来,仪器的小型化发展以及微机电系统(MEMS)技术工艺的发展带动了电容薄膜真空计的发展。其中,MEMS型电容薄膜真空计能将电路和敏感元件集成在同一芯片上,具有体积小、能耗低的优点,能广泛的运用在工业测量、深空探测等领域,是真空计量仪器研究热点之一。然而,体积小伴随着的测量范围窄、输出线性度不高、长久密封困难和残余气体影响问题都制约着真空计的商品化发展。针对上述的技术瓶颈,研究者提出了不同的技术方案来克服。文中总结相关的研究报道后对问题的缘由以及相应解决措施进行了分类整理与分析,对文献报道的MEMS型电容薄膜真空计进行了对比分析。最后,对MEMS型电容薄膜真空计的发展前景提出了展望。     

浅谈机电一体化的发展及趋势

机电一体化是指在机构得主功能、动力功能、信息处理功能和控制功能上引进电子技术,将机械装置与电子化设计及软件结合起来所构成的系统的总称。机电一体化是现代科学技术发展的必然结果。文章概述了机电一体化的核心技术,分析了机电一体化发展进程,提出了机电一体化向智能化迈进的趋势。     

等离子体化学气相淀积法(PCVD)生长氧传感器薄膜材料

稳定化 ZrO_2是目前已实用化的氧离子导体材料。由于工业过程自化的要求,传性感器的小型化、集成化、智能化已成为当前发展的趋势,各种薄膜型氧传感器元件的研制开始活跃起来~([1])。在众多的薄膜工艺中,PCVD 法优点突出,控制方便,尤其低压等离子体在低温所具有的高内能和活化能(其电子温度10~4～10~5K),为获得许多新型     

MEMS型电容薄膜真空计的关键技术研究进展

近二十年以来,仪器的小型化发展以及微机电系统(MEMS)技术工艺的发展带动了电容薄膜真空计的发展。其中,MEMS型电容薄膜真空计能将电路和敏感元件集成在同一芯片上,具有体积小、能耗低的优点,能广泛的运用在工业测量、深空探测等领域,是真空计量仪器研究热点之一。然而,体积小伴随着的测量范围窄、输出线性度不高、长久密封困难和残余气体影响问题都制约着真空计的商品化发展。针对上述的技术瓶颈,研究者提出了不同的技术方案来克服。文中总结相关的研究报道后对问题的缘由以及相应解决措施进行了分类整理与分析,对文献报道的MEMS型电容薄膜真空计进行了对比分析。最后,对MEMS型电容薄膜真空计的发展前景提出了展望。     

现场真空校准装置的设计

基于客户提出的在工作现场对真空计进行校准的切实需求,研究并设计了现场真空校准装置。该装置主要由供气和进样模块、抽气模块、压力衰减模块、压力测量与校准模块、烘烤模块等五部分组成。考虑到现场环境对真空计的影响和校准装置易于携带、小型化的要求,设计中采用了模块化分体式结构,复合了静态比较法、动态比较法和压力衰减法等真空校准方法。可根据不同的校准需求,选配不同的模块和方法实现对真空计的校准。现场真空校准装置预计达到的技术指标是,校准范围为10-4～105Pa,合成标准不确定度小于7%。     

电网调控一体化运行管理模式研究

现代化电网的大规模扩建的形式下,电力企业中应运而生新的管理模式,即电网调控一体化运行管理模式。该管理模式顺应了时代发展的趋势,它与以往的管理模式不同,它在实际电力企业管理中具备智能化,集成化,自动化以及高效化的优势。对于电力企业而言,最为重要的是电网调控工作,因此现代电力企业已经把电网调控一体化作为关键的发展战略。     

工厂安防系统中自动检测与诊断技术发展研究

随着信息技术和计算机技术的发展,有效地促进了自动检测与诊断技术在安防领域的广泛应用,不断与安防技术融合,形成了具有安防特点的现代智能检测技术。随着自动检测与诊断技术在安防领域需求的不断增长,网络化、集成化、智能化将成为工厂安防自动检测与诊断技术的发展方向。     

Development of vacuum metrology in National Institute of Metrology

Overview of the vacuum metrology development at the National Institute of Metrology, China is presented, including the different vacuum standards established years ago, the recently developed static expansion system and its characterization and the new compensated micro-manometer. Recent research of the performance of capacitance diaphragm gauges (CDGs) in Knudsen flow region, as well as the ongoing project on the constant pressure flow meter, micro-conductance measurement are also outlined.     

Vakuummeßgeräte für Totaldruck

Advances in the technical/technological development has resulted in a large growth of vacuum applications and the employment of vacuum techniques in almost all technical fields. In response to this expansion, the number of commercial vacuum gauges has increased. For the engineer or technician it has become more difficult, to make the right choice of the gauge. The present paper is intended as a guide. First, the most important measuring principles are dicussed. Thereafter modern equipment is decribed with application notes for different pressure ranges.     

Standardisierte Steckverbindung für aktive Vakuummeßköpfe

At the Gesellschaft für Schwerionenforschung, Darmstadt, an eight-pole interconnection for active vacuum gauges and corresponding controllers was standardized in collaboration with industry. It is suited for available gauges and gauges under development, which cover the whole technically interesting pressure range 10³–10¹² mbar. The interconnection contains the power lines for the gauge, the pressure signal as well as control lines for the various gauges. Just one type of connector is used thus facilitating stock keeping and use of different gauges. The chosen connector (known as modular connector) can be easily assembled without soldering. Furthermore, an encoder resistor installed in the gauge head allows an identification of the gauge by the controller. In this way, different gauges may be operated by the same controller or by the same PC plug-in module.     

真空计的发展概况与趋势

真空计量器具被广泛应用于各科学实验领域,种类繁多,样式各异。真空计的微型化是其主要发展趋势。概述了真空计的发展历程,重点对近年来真空计的最新发展作了梳理,并提出了某些特殊环境下真空度测量方法的构想。     

Stabilität von Hochvakuum-Meßröhren

Summary Hot filament and cold cathode ionization gauges are widely used in industry and research for pressure measurements in high and ultra high vacuum systems. Important applications are e.g. sputter and deposition systems. Since a long time it is accepted without a notice that the error of commonly used ionization gauges is typically 10% to 100%. The reason of this large error is the poor long term stability of the gauge sensitivity. If vacuum measurements must be precise and reproducible, long term stability of the vacuum gauges is the decisive issue. Only a stable gauge ensures correct control of processes. Also replacement of gauges should not produce differences in order to save time and money for new calibration. This paper reports experiments on the long term stability (several months) of widely used hot filament and cold cathode ionization gauges. Causes of timedependent instabilities are discussed. A new type of Bayard-Alpert gauge (STABIL-ION) is presented which offers a substantially improved long term stability compared to older design gauges.     

Entwicklung eines Ionisationsmanometers mit Feldemitterkathode

Development of an ion gauge with field emissionin cryogenic vacuum environments cathode for pressure measurements The measurement of UHV or even XHV pressures in low‐temperature vacuum systems has always been considered as a metrological problem. In principle, conventional hot‐cathode ion gauges can be used for pressure measurement in cryogenic vacuum environments. However, as a consequence of their high heat generation several disadvantages must be taken into account. With the development of an ion gauge of extractor‐type whose heat‐generating thermionic cathode is replaced by a non‐thermal field emission cathode, a promising approach to realize a reliable pressure gauge for cryogenic vacuum applications can be presented in this paper. The gauge equipped with a CNT cathode was investigated both experimentally and by numerical simulations in terms of their operating characteristics. It has been successfully demonstrated that the modified extractor gauge works reliably under low temperature conditions and provides meaningful pressure readings.     

Static expansion primary vacuum standard — Part 1: Determination of the volume ratio of the expansion stage

Measurement of volume ratio forms an essential part of the characterization of a static expansion system (SES) for the generation of pressures in the medium and high vacuum region. Because of the complexity of the vacuum chambers, it is not possible to determine the absolute volumes of the chambers involved. Hence an expansion process is resorted to, in which the gas enclosed in the small volume at a known pressure is allowed to expand, under isothermal conditions, into the large volume. The accuracy of the volume ratio thus determined depends on the stability of the vacuum gauges used for the measurement of initial and the final pressures and the ambient temperature. High accuracy resonant silicon gauges (RSGs) of two different ranges, one 130 kPa full scale and the other 1 kPa full scale for measurement of the initial and final pressures are found to be useful. This paper reports the results obtained with these RSGs for the measurement of the volume ratio of the National Physical Laboratory, India (NPLI) SES which is nominally 2820. With the use of the RSGs, and calibrated platinum resistance thermometers (PRTs) mounted inside the vacuum chambers, it has been possible to measure the volume ratio within the relative expanded uncertainty (k = 2) of 0.0014. The results of the volume ratio determination exercise are given in this paper while the Part 2 of this paper will discuss the procedure for the calibration of spinning rotor gauges on the Static expansion primary standard.     

Design and Implementation of Intel ligent Water Meter Reading System

With the rise of intelligent residential housing project and the implement of intelligent meter reading system,the four become the typical representative at the same time,they also become the short board of the old residential intelligent direction and constraints. As one of the four meter is an important measurement tool to save water resources. In the process of the development of society and technology,different types of meter reading methods have been derived,but there are still many problems,such as difficulty,time consuming,error copy,misreading. With the current mature image processing technology, the Internet technology and the rapid development of handheld intelligent terminal,the paper develop a meter reading system base on the Android system. The system can reduce the work intensity and the cost of meter reading,and it can make up the blank which old district and the mechanical meter reading can not be intelligent.     

Microstructured vacuum gauges and their future perspectives

New prototypes and concepts of microstructured vacuum gauges have been developed by using the fabrication technologies for micro electro mechanical systems (MEMS). The realization of such microstructured gauges requires sophisticated fabrication processes such as thin film deposition, photolithography and etching techniques. This approach of MEMS vacuum gauges is demonstrated by a few examples.Micro-Pirani gauges are based on the principle that the heat transfer between two surfaces is proportional to the number of molecules (and hence the pressure) transferring the heat, when the mean free path in the gas is larger than the distance between the surfaces. In contrast to conventional Pirani gauges with heated thin wires, in a micro-Pirani gauge the heat transfer takes place between an extremely thin heated membrane and the surrounding. The thin membrane (200-nm thick) is realized by deposition of siliconoxide/siliconnitride, photolithography and anisotropic etching of silicon wafers. Heating is performed by a meander-shaped aluminum thin film heater in the center of the membrane. This micro-Pirani gauge shows a high sensitivity in the pressure range between 10⁻⁴ and 100 mbar. By using a silicon “microbridge” with 10 μm small gap between heated membrane and surrounding, the pressure sensitivity of the chip is extended up to 1000 mbar.Similar concepts are presented and discussed with respect to the miniaturization of spinning rotor gauges. The new concept is based on the application of microfabricated disks (instead of spheres) and of electrostatic instead of magnetic driving forces. The extension of the sensitivity range for miniaturized spinning rotor gauges is also discussed.Finally, new perspectives for mechanical vacuum gauges are demonstrated. By application of micromechanical processes, very thin stress-compensated membranes can be fabricated which enable sensitive mechanical gauges even for pressures in the high vacuum range. First, experimental results with respect to these membranes are represented.     

Field emitter-based vacuum sensors

The subject of this article is to review the current state of the art and the trends of the development of vacuum gauges using various types of cold-cathode electron sources (e.g. silicon field-emitter arrays, emitter arrays of the Spindt-type, carbon-based field emitters, MIM cathodes, p-n junctions). Recent progress in design and fabrication of novel vacuum pressure sensors based on field-emitter cathodes is described and discussed. The advantages and the problems of such gauges are briefly reviewed.