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本文叙述了8710型热导池检测器(TCD)的特性。检测器中的导线从池的两端引出,使池体积减小到44μL。热丝元件的弓架在池中极短,弓架引起的热效应大大减少,全部热效应能够最大限度地作用在热丝上。文中对各设计参数做了较精确的计算。 相似文献
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文中采用MEMS技术加工研制了一种新型热导检测器,这种微型热导检测器采用电阻率高、电阻温度系数大的Pt热敏电阻,利用MEMS技术将Pt薄膜沉积在Pyrex 7740玻璃上并通过剥离技术获得热敏电阻,而气体通道以及热导池是通过深刻蚀在硅片上刻蚀得到,热导池的体积为0.4 μL.这种热导检测器具有灵敏度高,不受气流影响,不易氧化等特点,适用各种混合气体分离检测. 相似文献
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毛细管柱色谱技术越来越被广泛应用.毛细管柱样品容量小,需要配用高灵敏度和小死体积检测器.目前绝大部分毛细管色谱分析都采用离子化检测器,其中以火焰电离检测器(FID)为最多.但FID-毛细柱系统不适合分析非烃类、惰性气体、H2O以及在火焰中难以电离的物质,应用有局限性,所以,美国惠普(HP)公司推出的微型热导池与毛细柱联用技术,引起了色谱工作者的极大兴趣.上海雷磁创益仪器仪表有限公司生产的GC8850气相色谱仪,除了FID外,还带有高灵敏度微型热导池,可与毛细柱联用,初步应用令人满意. 相似文献
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本文针对色谱仪热导检测器电桥的工作特点。分析了用数字电位器替代机械电位器实现电桥自动调衡的两种方案,并根据较好的方案制作了热导检测器电桥的自动调衡电路,在实际应用中达到了理想的效果。 相似文献
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利用电导检测器离子色谱建立了氰根的分析方法,考察了该分析方法的检测下限、线性范围、标准误差(RSD)以及加标回收率.在高频热解设备中对神府煤和稻草进行了快速热解实验,利用NaOH溶液吸收法将热解气中的HCN转化为氰根离子,利用所建立的检测方法对氰根进行定量.结果表明,信噪比为3时该分析方法的检测下限为0.01 mg/L,在0.1~50 mg/L范围内线性关系良好,标准误差(RSD)小于3%,加标回收率为90%~105%.对HCN吸收液样品进行检测时发现氰根与其他杂质离子分离效果较好,3次重复实验的重现性良好.所建立的HCN吸收方法和氰根检测方法能够满足煤和生物质热解时HCN生成率的考察要求. 相似文献
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A formula is obtained for estimating the contact thermal conductivity of a dry joint. 相似文献
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针对气相色谱热导检测器的弱信号失真问题,研究与设计热导检测器的弱信号测量电路及其单片机控制系统,进一步提高气相色谱热导检测系统的灵敏度和可靠性。 相似文献
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Xiaoling Zhang Qingduan Meng Qian Yu Liwen Zhang Yanqiu Lv 《Journal of Mechanical Science and Technology》2013,27(6):1809-1813
When exploring the buckling mechanism in indium antimonide (InSb) detector, the global square checkerboard buckling pattern reappears in finite element simulation results. The contributions from the three layered materials to the deformations along the Z-direction are systematically analyzed. Analysis of results shows that the buckling deformation originated from the thermal difference between silicon readout integrated circuits (silicon-ROIC) and the intermediate layer directly above. Furthermore, the buckling pattern is determined by indium bumps array. After passing through the 10 μm intermediate layer, the deformation amplitude is significantly reduced from 2.23 μm to 0.24 μm. Afterwards, passing upward through the 10 μm InSb chip, the maximal deformation is further decreased to 0.09 μm. 相似文献
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This paper considers the use of contact electrical conductivity to analyse boundary lubrication at various temperatures. The main mechanisms of contact conductivity within the temperature range typical of lubricated tribosystems are discussed. Special equipment is described for temperature investigation and experimental data are presented on electrophysical methods. Model experiments with static nominal point contacts bring to light some peculiarities of the behaviour of boundary films when heated. Analysis of electrical and frictional characteristics under sliding shows the contact resistance method to be promising in the thermal testing of boundary films. 相似文献
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热导检测器 (TCD)是GC - 14A气相色谱仪常用检测器之一。但TCD故障往往不易准确判断 ,处理不当还会扩大故障部位。本文在排除电路和气路方面的原因外 ,分析了TCD常见的三种故障现象 ,提出了相应的处理方法。(1)开机后基线不稳 ,噪声大或基线严重漂移。故障分析 :可能是TCD被污染 ,从TCD工作时间长短可粗略推断TCD受污染的程度。处理方法 :对于轻微污染 ,可将TCD的气路进口和出口拆下 ,用 5 0mL注射器依次将丙酮、无水乙醇和蒸馏水从进气口反复注入 5~ 10次 ,用吹气球从进气口处缓慢吹气 ,吹出杂质和残余液体 ,然… 相似文献
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Starecki T 《The Review of scientific instruments》2010,81(12):124702
The paper presents the design of a low-noise preamplifier dedicated for condenser measurement microphones used in high sensitivity applications, in which amplifier noise is the main factor limiting sensitivity of the measurements. In measurement microphone preamplifiers, the dominant source of noise at lower frequencies is the bias resistance of the input stage. In the presented solution, resistors were connected to the input stage by means of switches. The switches are opened during measurements, which disconnects the resistors from the input stage and results in noise reduction. Closing the switches allows for fast charging of the microphone capacitance. At low frequencies the noise of the designed preamplifier is a few times lower in comparison to similar, commercially available instruments. 相似文献