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低温装置中温度测量的热沉问题 总被引:2,自引:0,他引:2
文中讨论了低温装置中的热沉问题。为减少因电引线导热对温度计的热负荷 ,提高温度测量的精度 ,在温度计的引线中加入热沉将是非常必要而且有效的手段。文中解决了不同边界条件下所需的热沉长度的求解问题 ,并讨论了其实际应用 相似文献
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提出一种波长检测技术实现温度测量的方法,利用FBG传感器对温度等物理量实施监测,具有测试精度高,应用场合不受限制等特点,当环境参数发生变化时,光纤光栅的有效折射率和光栅周期会受到影响,将引起光纤光栅峰值波长的偏移,依据反射光谱结构的变化,可知道其温度的变化趋势。实验测试结果表明,在温度变化0.1°,波长变化1pm,温度和波长具有良好的线性关系。 相似文献
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在EAST托卡马克核聚变实验装置中,超导磁体系统的热负荷计算、超导性能和及其运行稳定性等都与磁体运行温度有很大关系,因而要求超导磁体系统的氦冷却管路的温度测量有较高测量精度和稳定性。从氦温度测量方法、专用温度监测仪的配置、用户自标定温度传感器的温度特性曲线的生成出发,介绍专用温度监测仪在EAST超导磁体系统氦温度测量中的具体应用。同时介绍了仪器监控的硬件架构和基于Lab VIEW的仪器监控软件设计。经过2轮实验运行,表明该应用提高了氦温度测量的精度、稳定性和工作效率。 相似文献
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Arup Lal Chakraborty 《Optics Communications》2007,274(2):396-402
This article discusses a powerful calibration technique that compensates for the temperature dependence of the Stokes signal in a Raman distributed temperature sensor. The Stokes signal is conventionally used for normalization since its scattering cross-section is a weaker function of temperature than that of the anti-Stokes signal. The potential of this temperature dependence of the Stokes signal to introduce errors in measurements has received only cursory mention in the literature. We show that this effect degrades the temperature accuracy by as much as 90%. Additionally the heavy fiber attenuation at the operating wavelength also makes calibration non-trivial. The technique described implements a corrective mechanism for this temperature dependence, offers the additional benefit of self-referencing of a heated curve rather than referencing to the fiber at room temperature, and demonstrates the viability of such a system despite the heavy fiber attenuation at the operating wavelength. This obviates the impractical and erroneous approach of storing an initial room temperature profile for subsequent temperature calculation. This dynamic self-referencing adds substantial immunity to the tolerances in the actual numerical values of the Raman wavelengths thereby making the system robust. 相似文献
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低温液晶显示器-加固理论与实践 总被引:1,自引:0,他引:1
该文对液晶显示器(LCD)低温加固的理论进行分析和研究。在此基础上,介绍一种新研制的机载低温液晶显示器。在显示器中设计了一套透明的加热、真空保温、抗眩光及电磁屏蔽装置,低温工作时,只需非常小的加热功率,就能使液晶显示器正常工作,同时可以利用该装置中的氧化铟锡(ITO)导电膜层满足显示器视窗对防眩光及电磁兼容(EMC)特性的要求。这种新型低温加固型LCD集多种特殊功能于一体,具有功耗低、亮度高、可靠性好、抗眩光、EMC性能好及结构便于组装等多项显著优点。 相似文献
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Plasma enhanced chemical vapor deposition (PECVD) is one effective method to prepare graphene at low temperature in a short time. However, the low temperature in PECVD could not provide substrate a proper state for large area and few layer graphene preparation. Herein, we propose a two-step method to grow graphene on Cu foils. In the first step, in order to acquire a smooth and oxide-free surface state, methanol was used as a reductant to pretreat Cu. In the second step, graphene films were prepared on Cu foils by PECVD using CH4 as carbon source with H2-free. Few-layer graphene sheets with diameter about 1 μm under low temperature (700 °C) and at a short time (10 min) on well pretreated Cu foils were successfully gotten. The effect of methanol pretreatment on graphene synthesis and the graphene growth mechanism on Cu substrate by PECVD are analyzed comprehensively. 相似文献
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光声测温是一种利用光声效应来进行温度监控的新方法,具有非侵入式、高灵敏度和探测深度较深等优点.但现有的单波长光声测温方法极易受到系统及测量环境干扰而导致测量精度降低.为了解决这一问题,本文提出了一种双波长光声温度测量方法.在光声测温理论的基础上,分析推导了双波长光声测温的基本原理,并进行了仿体及离体组织样品的双波长光声测温实验.实验结果显示,与传统单波长模式相比,双波长模式下的光声温度测量误差明显减小,测量精度平均提高35%以上.研究结果表明双波长光声测温方法能够有效提高光声温度测量的精度和稳定性,可作为一种更精准的光声温度监控方法应用于医疗手术等领域. 相似文献
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针对合金材料在温度变化过程中电导率的变化引起性能改变问题,为此,设计了一套材料电导率测量系统.通过简单的操作就能测量从常温到低温下的材料电导率,并实现数据的显示、保存、打印和网络传输等功能.该系统利用温度校正方法,消除了温度变化给电导率引起的测量误差.该系统具有较高的测量精度,可广泛应用于不同材料的电导率测量. 相似文献