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将薄膜电真空计的测量室接于被测密闭容器,静态真空室接于一个比较容器,即组成一台压差式漏率测试仪,首先使两容器压力平衡,真空计读数为零。当被测容器存在漏孔时,真空计薄膜两侧形成压差,真空计指示读数,继而计算出该容器的漏率。应用商品真空计在抽真空测试时,检测的最小可测漏率达10^-4-10^-5Pa.Ls;而在充压测试时,因受气体温度变化的影响。灵敏度会降低几个量级。该仪器有可能具备寻找漏孔位置和确定 相似文献
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许阳光潘晓霞刘晓艰王彤蔡悦曾祥兵杜宏伟廖彬 《真空科学与技术学报》2018,(10):839-845
围绕容积为104cm^3量级的密闭容器开展背压法漏率检测关键技术研究,分析了压氦压力、压氦时间、容器内外壁气体解吸附等因素对实验结果的影响机制,建立了一套可用于大容积密闭容器的背压法检漏流程。理论和实验研究结果表明,将背压法用于预制漏率为10^(-6)Pa·m^3/s量级的大容积密闭容器的漏率检测是可行的。随着漏孔漏率的降低(低于10^(-7)Pa·m^3/s量级),试验件的最低可检漏率也将逐渐低于氦质谱检漏仪的有效检测漏率,而由于被检对象的本底漏率值无法提前获知,将造成将背压法用于更低漏率的大容积密闭容器的漏率测试结果误差极大地增加。相关研究结果对于大容积密闭容器的漏率检测具有一定的理论指导价值。 相似文献
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《真空科学与技术学报》2018,(10)
围绕容积为104cm~3量级的密闭容器开展背压法漏率检测关键技术研究,分析了压氦压力、压氦时间、容器内外壁气体解吸附等因素对实验结果的影响机制,建立了一套可用于大容积密闭容器的背压法检漏流程。理论和实验研究结果表明,将背压法用于预制漏率为10~(-6)Pa·m~3/s量级的大容积密闭容器的漏率检测是可行的。随着漏孔漏率的降低(低于10~(-7)Pa·m~3/s量级),试验件的最低可检漏率也将逐渐低于氦质谱检漏仪的有效检测漏率,而由于被检对象的本底漏率值无法提前获知,将造成将背压法用于更低漏率的大容积密闭容器的漏率测试结果误差极大地增加。相关研究结果对于大容积密闭容器的漏率检测具有一定的理论指导价值。 相似文献
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温度变化对漏孔漏率的影响 总被引:2,自引:1,他引:1
分析了漏孔在温度夹变时漏孔的热物理过程和与之相适应的漏孔漏率变化。认为漏孔在突然处于低温状态时,漏率变化的主要因素是示漏气体滞粘系数随温度的变化而造成,漏孔尺寸随温度变化引起漏率变化是次要的。在非稳定状态时,漏率随时间呈指数式变化。 相似文献
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陈庆林 《真空科学与技术学报》1983,(3)
脉冲超声波探伤仪发射的超声波,传入待检部位,超声波直线传播直至碰到漏孔,产生回波讯号并被仪器接收。利用漏孔回波讯号被仪器接收这种方式判断容器是否有漏孔以及这些漏孔的位置,根据回波讯号测定漏孔的漏率, 相似文献
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A study of the uncertainties in calibration using capacitance diaphragm gauges as reference standard in the range from 1000 mbar to 10−3 mbar is presented. The contributions to the expanded uncertainty are: (i) Uncertainty from the calibration certify of the reference standard; (ii) Long-term stability or shift; (iii) Uncertainties inherent to the reference standard; (iv) Uncertainties derived from the calibration chamber; and (v) Uncertainties derived from the calibration procedure. These contributions have been determined for four reference standard capacitance diaphragm gauges of 1.3 mbar, 13 mbar, 130 mbar and 1300 mbar full scale used in routine calibration. Long-term stability or shift jointly with the uncertainty displayed in the calibration certifies issued by a National Metrological Laboratory are the main contributions to the expanded uncertainty. Values of the shift for each of the reference standard for a period of several years are presented and discussed. Best-expanded uncertainties obtained from calibration of a gauge of similar characteristics to the reference standards are:
10−3-1 mbar 4-0.2% of the reading 1-13 mbar 0.2% of the reading 13-130 mbar 0.2-0.08% of the reading 130-1300 mbar 0.2-0.06% of the reading - Full-size table
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介绍用磁控溅射制作的从大气往真空约覆盖5个量程的“绝对型”电容薄膜真空规,以及与该真空规配套的真空计的电路。该真空计测量范围为1.3~105Pd,真空规与电容信号检测电路置于同一金属壳内,以避免外界干扰。规的恒温胜温度波动小于±0.1℃,有效地降低了温度的影响。电路的非线性小于0.4%,高真空下北输出漂移小于0.1%,在13~105Pa各量程内,最大校准误差小于读数的4%。 相似文献
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CEGB-Planer capacitance strain gauges are used extensively for monitoring the deformation of components operating in the creep range. However, there are significant differences between the way the gauges are installed for use and the way they are installed for calibration. This paper describes the various types of calibrations that have been carried out to identify the errors associated with these differences and the results show that, providing the manufacturers' recommendations are adhered to, the errors are acceptably small. 相似文献
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Determination of band offsets in a-Si:H/c-Si heterojunctions from capacitance-voltage measurements: Capabilities and limits 总被引:1,自引:0,他引:1
The capabilities and limitations of the well-known C-V technique for the determination of the conduction band offsets in (n)a-Si:H/(p)c-Si heterojunctions are presented. In particular, the effects due to the presence of an inversion layer in c-Si and a non-negligible defect density at the a-Si:H/c-Si interface on the reliability of the C-V intercept method are discussed. The influence of the Fermi level positions in (p)c-Si and (n)a-Si:H on the inversion layer formation and the influence of the interface defect density have been analysed using numerical simulations and experimental measurements. 相似文献
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An international project to search μ→eγ decay includes the use of a liquid xenon gamma ray detector. So, a liquid level meter working at a low temperature with low outgassing is needed and the prototype is constructed. The meter shows the liquid level by measuring the capacitance between electrodes with small intervals immersed in the liquid. The operation was successful with the estimated precision of 1 mm in RMS or better. 相似文献
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Yinghua WEI Lixin ZHANG Wei KE 《材料科学技术学报》2006,22(1):108-112
Electrochemical impedance spectra (EIS) technique was adopted to evaluate the water sorption behaviour of an epoxy freestanding film in a 0.5 mol/L sodium chloride solution at 20℃. The methods for obtaining the capacitance data from EIS data were compared. The Brasher-Kingsbury (BK) and corresponding modified version (Modi-BK) models were used to calculate the water uptake in film and the gravimetric results were presented for comparisons. According to the discussion of the discrepancy of water content in film obtained from two models, a new method was proposed to indicate the organic film structure. 相似文献
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大型机械工件高精度同轴度误差测量的新方法 总被引:1,自引:0,他引:1
本文介绍一种以标准钢丝作基准,借助于专用检具和电容测微仪,以非接触方法对方法对大型机械工件进行同轴度误差测量的新方法,同时,也对组成该检测系统的电容测微仪的标定方法和专用检具的设计特点作了概括说明。 相似文献
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Ying Tian Jingwang Yan Liping Huang Rong Xue Lixing Hao Baolian Yi 《Materials Chemistry and Physics》2014
Nickel hydroxide consisting of loosely packed nanospheres was synthesized as positive electrode material for an asymmetric capacitor based on Ni(OH)2 and activated carbon (AC). Two series of supercapacitors were fabricated to investigate the effects of the single electrodes of Ni(OH)2 and AC on the electrochemical performance of asymmetric Ni(OH)2–AC capacitor. Parameters including cell voltage window, specific capacitance and cyclic stability were assessed. In one series of supercapacitors, mass of Ni(OH)2 was excessive while mass of AC was varied, the AC electrode thus constrained both the capacitance and the upper limit of cell voltage. Deficiency of AC resulted in lower specific capacitance and narrower cell voltage window but benefited to cyclic stability. In the other series of supercapacitors, the mass of AC was excessive whereas the mass of Ni(OH)2 was changeable in each cell, Ni(OH)2 electrode thus dominated both the capacitance and the lower limit of cell voltage. As a consequence, deficiency of Ni(OH)2 led to higher specific capacity and wider cell voltage window as well as lower cyclic stability. These results can contribute to improving understanding of and optimizing performance of asymmetric Ni(OH)2–AC capacitor. 相似文献
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