低温绝热容器中皮拉尼真空计取代热偶真空计的可行性分析

在低温绝热容器夹层真空度的测量中,皮拉尼真空计和热偶真空计较适用,目前热偶真空计应用较多。从测量范围、测量精度、测量温度、互换性、远程监控、检漏能力和性价比等方面,对皮拉尼真空计和热偶真空计的性能进行了比较,得出皮拉尼真空计更适用于低温绝热容器夹层真空度测量的结论。最后列举了目前国外几种典型的商用皮拉尼真空计和热偶真空计的技术参数。     

真空环境下电容薄膜规测量偏差的原因分析

在某大型航天器的调试试验中,需使用电容薄膜规(以下简称薄膜规)进行密封舱内真空度测量,结果发现薄膜规测量数据出现了较大的偏差.本文即对这一问题进行原因分析,提出在真空环境下,薄膜本底偏移量是产生偏差的最重要原因,并有针对性地采取解决措施.     

石英真空计的工作原理

本文介绍石英真空计的原理及石英晶振的特性.     

单片机在DL-8型电离计中的应用

介绍用单片机实现DL—8型电离真空计的智能化设计，在设计中，用单片机完成了多路电参数切换和控制；用振荡反馈电路控制可控硅实现发射电流稳定；用高输入阻抗运放实现微弱信号的精确测量。     

Miniature and MEMS-type vacuum sensors and pumps

In the paper, the observable trends of the actual research and development of selected types of miniature and MEMS-type vacuum sensors are presented. Some information about the new types of active vacuum gauges, which are offered by the leading manufacturers of the vacuum measurement instruments, is given. Next, the list of MEMS devices that need vacuum for proper operation is presented. Some aspects of vacuum-encapsulation of MEMS devices, on wafer level and package level are shown. The new conceptions of obtaining and maintenance of high and ultra-high vacuum in MEMS devices are described. They concern the conception of integration of a miniature orbitron pump on-chip with MEMS-type device or with vacuum part of the portable advanced instruments such as electron microscope, ion mass spectrometer, and free electron laser.     

嵌入式低温真空测量系统

介绍用于G-M制冷机真空测量的嵌入式低温真空测量系统硬件和软件设计,它由嵌入式真空测量控制模块与PC计算机系统组成.其特点是该真空测控模块可嵌入任意待测对象或系统,通过PC计算机的窗口软件选择配置仪器量程、精度和传感器,满足不同工作情况要求,并具有参数存盘、动画显示、打印等功能.     

岛津PEC-A_2样品表面处理装置真空系统故障维修

PEC—A_2样品表面处理装置是岛津公司为EPM-810Q电子探针样品表面进行喷金处理装置,其主要包括抽真空系统和喷金电流控制系统,抽真空系统由机械泵和油扩散组成,真空度可达到6.7×10~3Pa torr。     

Electronic vacuum gauge with thermocouple transducer

Translated from Izmeritel'naya Tekhnika, No. 6, p. 20, June, 1989.     

用线性真空规测量小孔分子流流导的方法研究

提出了用线性真空规测量小孔分子流流导的方法,该方法利用了线性真空规两次测量压力的比值,避免了真空规测量绝对压力引入的不确定度,从而有效减小了小孔流导的测量不确定度.文章介绍了小孔流导的测量原理、测量装置和测量结果,小孔流导测量的合成标准不确定度为0.29%.     

真空比对法校准装置的研究

真空比对法校准装置采用了动态直接比对法、静态直接比对法和静态膨胀法,在一台装置上复合了三种方法,满足了拓宽量程的需求.该装置可以1×105-5×10-4 Pa范围内的各类真空规进行校准,是一种结构简单、操作方便、检定效率高、实用性强的真空标准装置.整套装置由涡轮分子泵、校准容器、副标准真空计和金属膨胀阀等部件组成,主要技术指标符合国际标准化组织和国内有关真空标准的规定.     

Calibration of vacuum gauges in an expanded low pressure range

A new original method is described for calibrating vacuum gauges making it possible to cover a range of intermediate pressures from 0.01–0.1 to 1–10 MPa. Experimental data confirm the efficiency of the suggested procedure.Translated from Izmeritelnaya Tekhnika, No. 12, pp. 43–44, December, 2004.This revised version was published online in April 2005 with a corrected cover date.     

Ionization vacuum gauge with a carbon nanotube field electron emitter combined with a shield electrode

The applicability of carbon nanotubes to an electron source for a Bayard-Alpert type vacuum gauge has been investigated. Three gauge configurations are designed to optimize the gauge performance. The optimized gauge, in which an additional shield electrode is fixed on a gate electrode, exhibits good measurement of linearity between ion current and system pressure from 10⁻⁷ to 10⁻² Pa. A gauge sensitivity of 0.05 Pa⁻¹ has been achieved under 100 μA emission current for nitrogen, comparable with 0.07 Pa⁻¹ of commercial ionization gauges.     

I~2C总线接口单片机在真空计设计中的应用

介绍了使用具有 I2 C总线接口的单片机并应用 I2 C总线技术进行真空计系统的设计。     

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.     

Calibration of ultrahigh vacuum gauge from 10 Pa to 10 Pa by the two-stage flow-dividing system

A new two-stage flow-dividing system has been developed for the calibration of ultrahigh vacuum gauges from 10⁻⁹ Pa to 10⁻⁵ Pa for N₂, Ar, and H₂. This system is designed based on the techniques for our previously developed calibration system in the range from 10⁻⁷ Pa to 10⁻² Pa. Three modifications were performed to extend the calibration pressure to a lower range. The relative standard uncertainty of the generated pressure (k = 1) is in the range from 2.3% to 2.6%, from 10⁻⁹ Pa to 10⁻⁵ Pa. The characteristics of ultrahigh vacuum gauges were also examined by using this system. The stabilities of the pressure reading, the linearity, the temperature dependence, and the long-term stability were examined. These results show that the calibration of ultrahigh vacuum gauges is possible in the range from 10⁻⁹ Pa to 10⁻⁵ Pa for N₂, Ar, and H₂ with the uncertainty of about 6.0% (k = 2) by this new system.     

常用真空计的测量范围及其性能

介绍几种测量范围为10-8～105 Pa的常用真空计,其应用十分广泛,性能较好,价格较低.     

A vacuum sensor using field emitters made by multiwalled carbon nanotube yarns

A newly developed vacuum sensor using carbon nanotube (CNT) field-emission has been designed. The fabricated device is an ionization gauge with a silk-like CNT yarn cathode, and the vacuum is indicated by the ratio of the ion current to the electron-emission current. The metrological characteristics of the sensor were studied in a dynamic vacuum system. It showed good linearity ranged from 10⁻⁴ to 10⁻¹ Pa. Taking advantage of the field-emission cathode, the power consumption is only about 5.5 mW. Moreover, comparing it to the conventional thermionic cathode, the CNT yarn cathode is more miniature and a cold cathode with no obvious thermal outgassing effect. Due to these features, the sensor described here could have potential applications in measuring vacuum inside sealed and miniaturized devices.     

压敏电阻用于低真空测量的研究

研究了将压敏电阻用于低真空的测量，包括规管和电路，研制成了新型DL-4型真空计。该计测量范围为102～105Pa，性能好，价格便宜。介绍了该真空计的原理、结构与特性。     

Grain structure in cathode spot trail of low vacuum arc discharge

Low vacuum arc discharge treatment in 10 Pa is applied to cleaning of a stainless steel plate, the surface of which is covered with an oxide layer. During the discharge, several luminous cathode spots move continuously in random directions on the surface of the stainless steel plate. They remove the oxide layer owing to their high energy density and leave their trail on the sample surface. Microscopic observation reveals a chain structure of metallic grains along the center of the cathode spot trail. Some chemical agents put on the oxide layer before cleaning affect on the size and the number density of the grain, which leads to the different surface roughness after treatment.