共查询到20条相似文献,搜索用时 15 毫秒
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A technique is described for the measurement of fluid flow using an optical-fibre transducer. The flowmeter has no mechanical moving parts and causes no pressure drop in the liquid stream. The optical system and the detection electronics are intrinsically very simple. Results from a prototype meter are given, and improvements in this design, particularly in the turbulence characteristics of the meter tube, should improve measurement accuracy to an estimated ±5%. 相似文献
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Careful investigation of the cooling of a heated body in a flow shows that in integrated silicon technology a very small flowmeter can be made with a well defined direction-sensitive response over a wide range of flow speeds. 相似文献
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涡街流量计的二次仪表设计 总被引:1,自引:0,他引:1
流量测量在经济建设和社会生活的各个方面得到广泛的应用.涡街流量计通常由流量传感器(又称一次仪表)和流量显示器(又称二次仪表)组成,介绍一种流量计的设计思路,给出硬件组成和软件框图. 相似文献
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An integrated laser blood flowmeter 总被引:1,自引:0,他引:1
We have constructed a very small and lightweight blood flowmeter using micromachining and surface mounting techniques for a wearable health monitoring system. The hybrid integrated structure of the optical system incorporates a InGaAsP-InP distributed feedback laser diode (DFB-LD) with a wavelength of 1310 nm, an edge-illuminated photodiode (PD) and a polyimide waveguide on silicon substrate (2 mm /spl times/ 3 mm). This integrated flowmeter can be positioned directly on the tissue and permits real-time monitoring of capillary microcirculation. In-vivo measurements of blood perfusion in a finger confirm the feasibility of the blood flowmeter. 相似文献
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Electromagnetic inverse scattering of multiple two-dimensional perfectly conducting objects by the differential evolution strategy 总被引:4,自引:0,他引:4
Anyong Qing 《Antennas and Propagation, IEEE Transactions on》2003,51(6):1251-1262
Electromagnetic inverse scattering of multiple two-dimensional (2-D) perfectly conducting objects with transverse magnetic (TM) wave incidence by the differential evolution strategy (DES) is presented. The governing electric field integral equations for the scattering problem are expressed as surface integral over the cylinder contours. The cylinder contours are approximately represented by closed cubic B-splines local shape functions in local polar coordinate system. The inverse problem is to locate the cylinders and to reconstruct their shape with or without a priori knowledge of the number of cylinders. It is cast into an optimization problem and is solved using the DES. Both synthetic and real reconstructions are carried out. The reconstruction results agree with the true profiles very well. Comparison with the real-coded genetic algorithm has been carried out. It has been observed that the DES outperforms the real-coded genetic algorithm. 相似文献
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Leilabady P. Akhavan Jones J.D.C. Kersey A.D. Corke M. Jackson D.A. 《Electronics letters》1984,20(16):664-665
The use of a monomode optical fibre sensing element in the measurement of flow velocities by an interferometric technique is described, in which the operating principle is the flow induced oscillation of the fibre caused by vortex shedding. The system has been demonstrated to show a linear response with water flows in the Reynolds number range 100?3500. 相似文献
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超声多普勒流量模拟器研究 总被引:1,自引:0,他引:1
相对传统的流量计,超声多普勒流量计测量适合于多种工况条件和液体类型的流量测量,在工业流量测量中具有广泛的应用前景。为了适应多普勒流量计性能测试和评估的需要,加快流量计的研制进程,本文通过对油田应用环境的分析,提出了基于DDS(直接数字式频率合成)技术的多普勒流量模拟器的设计。完成了硬件、固件程序及计算机软件的开发。应用... 相似文献
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The letter describes a fibre-optic mass flowmeter for liquids, which is based on the Coriolis effect. The flowmeter is optically powered, and employs interferometric detection. Experimental results are presented and discussed 相似文献
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设计了一种基于MSP430系列超低功耗系列单片机的涡轮流量计,通过无线模块实现主从控制器之间的数据和命令传送,通信时采用了“主一从”的方案。从控制器将传感器采集到的流量信号传送给主控制器,主控制器发送命令控制从控制器的测量、阀门的开、关等动作,主控制器通过CDMA网络传送数据给控制室。流量计结构简单、轻巧、反应灵敏、安装维修方便,不需要铺设通信电缆。 相似文献
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超声波流量计因为具有不接触被测介质等优点,已经被不断研究并应用在许多领域,发挥了巨大的作用。设计了基于DSP,以多普勒效应为原理的超声波流量计,完成了硬件设计和软件设计。最后对FIR数字滤波器和FFT算法进行了仿真,证明了方案的可行性。 相似文献
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设计了一种基于超低功耗单片机MSP430F149的涡轮流量计,运用单片机的片内定时器,捕捉涡轮传感器由于流体流过时叶片转动产生的脉冲信号,完成对流量信号的测量,通过无线数传模块传送流量数据,并且可以接收上位机的命令,来控制阀门动作。流量计结构简单、轻巧、反应灵敏、安装维修方便,不需要铺设通信电缆。 相似文献
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An optical fibre flowmeter is described which uses a single fibre mounted transversely to the fluid flow within the pipe. The fibre is vibrated by the natural phenomenon of vortex shedding, causing phase modulation of the optical carrier within. The modulation is detected at the fibre exit by the fibredyne technique, and the flow rate determined from the vibration frequency. 相似文献
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电磁兼容与电磁兼容设计 总被引:4,自引:0,他引:4
电磁兼容设计通常包括系统设计/分系统和分机设计,从工程实施上考虑,需要在结构和电路设计综合采取措施。系统/分系统设计要考虑系统内部能兼容工作,更要在EMC设计前,对系统/分系统工作环境进行调查。详细论述了有效并较易采用的一些方法及注意事项。设计中应采用投资少而系统效能又高的设计方案,以减少费效比。 相似文献