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双时间法在脉冲型流量传感器检定中的应用 总被引:3,自引:2,他引:1
设计了一种新型的双时间法计数器 ,并成功地应用于检定脉冲型流量传感器 .试验表明 :该计数器性价比高 ,使用方便 ,工作可靠 ,可以缩短检定时间 ,在一定条件下 ,可用较小的标准容器检定较大口径的流量传感器 ,并且比常规检定方法具有更高的计数精度 相似文献
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在火工品生产中,经常要对产品进行计数,以便进行分装和统计产量。自动记数的方式大致可以分为机械式和电子式两类。机械式计数器简单直观,容易掌握,抗干扰。但是体积较大,有噪音,不容易和自动定量仪、计算机等装置接口。此外,易产生火花,不利于火工品安全生产。电子计数器却具有体积小、无噪音、易于和其它装置接口等优点,在生产中正日益广泛地被采用。电子计数器是由一些二极管、三极管和其他电子器件组成的计数系统。按其采样、转换、显示方式的不同,可以组合成多种型式的计数器。由于计数显示器已有多种定型产品,计数装置的设计,重点在于设计计数传感器。 相似文献
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1系统整体框架设计
本系统是为了测量皮带轮在转动过程中轴向和径向产生的微小位移,于是,我们需要先确定能够胜任微小位移测量的传感器。之后根据确定的位移传感器设计信号处理计数电路,并通过单片机读取实时数据,通过串口传给上位机显示实时的数据。整个系统的总体结构图如错误!未找到引用源。所示。 相似文献
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以 123型水泥基压电复合材料作为传感元件制备了水泥基压电复合材料传感器。研究了水泥基压电复合材料传感器的频率响应、 线性性能以及应用于混凝土后的传感性能。结果表明: 当加载频率小于 5 Hz时 , 所有载荷下传感器输出电压的幅值均增大 , 但当加载频率大于 5 Hz时 , 所有载荷下传感器输出电压的幅值几乎与输入载荷频率无关 ; 传感器的输出电压幅值和输入载荷幅值之间存在明显的线性关系。水泥基压电传感器在实际混凝土结构中具有良好的传感特性 , 其输出电压与复杂载荷、 随机载荷和脉冲载荷均呈现明显的一一对应关系 ,且与输入载荷基本同步 , 不存在滞后现象 , 试验输出电压值与理论输出电压值也非常吻合。该传感器非常适合于土木工程结构的健康监测。 相似文献
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A new aggregate-like sensor using piezoelectric ceramic as sensing element was designed, fabricated and tested. The sensor
was made by bonding together two cuboids of hardened cement paste with a commercially available piezoelectric ceramic plate
in between, which is the sensing element. A new adhesive was developed during the fabrication of the sensor. The sensor was
tested on its basic performance with a charge amplifier measuring system. First, the frequency response of the sensor was
investigated in the general frequency range of civil engineering structure, which is from 0.01 Hz to 40 Hz. Then the relationship
between output and input of the sensor was tested. Finally, complex, random and square loads were applied to observe the performance
of the sensors. The excellent compatibility with concrete and the good sensing performance enable the aggregate-like sensor
to be easily embedded into concrete structures like a real aggregate and to reliably monitor the vibration of host structure.
There is a good potential for such a sensor to be used in structural health monitoring. 相似文献
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应力自感知水泥基复合材料是在传统的水泥或砂浆中添加特定导电材料或纳米材料复合而成的具有压阻效应的材料。利用这类材料的电阻率与其自身压应力存在一定对应关系的特性, 可以制成性能独特的应力自感知水泥基复合材料传感器。此类传感器因具有造价低、耐久性好、埋设工艺简单以及与混凝土材料相容性好等特性, 有望成为混凝土结构长期健康监测的新一代传感装置。本文作者从原材料选择、搅拌工艺、电阻测试方法以及传感器测试系统等多方面综合评述了应力自感知水泥基复合材料的研究进展。同时指出, 为促进其在工程中的应用, 对碳纤维水泥石电阻率的离散性、稳定性以及多向约束受力下电阻率的变化曲线等问题都必须进一步深入研究。 相似文献
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Fei Sha Shucai Li Dongyu Xu Shifeng Huang Rentai Liu 《Research in Nondestructive Evaluation》2017,28(2):61-75
A kind of strain-sensing-based piezoelectric sensor was fabricated, and the mixture of cement powder and epoxy resin was used as the packaging layer. A nondestructive strain sensitivity testing method based on strain-sensing capability of piezoelectric sensor is presented. The theoretical foundation indicates that output voltage of piezoelectric sensor and strain of structure keep linear relationship when corresponding parameters are ascertained. Quasi-static responses and low-frequency (0–40 Hz) dynamic responses of piezoelectric sensors and strain gauges are analyzed. The results show that the piezoelectric sensors are sensitive and can accurately reflect the strain variation of structures. The quantification of output voltage and strain is investigated, and quasi-static and dynamic sensitivities were acquired (159.52–515.48 mV/με). With increasing of vibration frequency, the area of hysteresis loop decreases, and the strain sensitivity of sensor increases. Combining sensitivities with output voltages of sensors, the strain variation of structures could be obtained, which exhibit great application potentials of piezoelectric sensors for structural strain monitoring in low-frequency vibrations in civil engineering. 相似文献
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目的 研究自1988年首次发布水泥包装袋国家标准以来我国水泥包装袋标准化历程,为标准的修改提供参考。方法 通过分析历次水泥包装袋国家标准(GB 9774、GB/T 9774)修订内容,从水泥包装袋的分类、制袋材料、袋型、物理力学性能、适用温度、牢固度、防潮性能等方面阐述水泥包装袋制袋技术标准化的更新改进。通过2018—2020年水泥包装袋产品质量普查,从防潮性能、物理力学性能、弃缝改糊、禁塑令、绿色包装等方面阐述水泥包装袋标准化必要性。结果 通过对比水泥包装袋新旧标准中防潮性能测试方法与指标要求,得出了水泥包装袋防潮性能标准化的趋势。结论 我国水泥包装袋制袋国际化程度较低,标准化工作需要进一步与国际接轨,以引领水泥包装产业发展。 相似文献
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根据火灾的特征与燃烧产物,设计了一种基于多传感器信息融合的火灾探测系统.该系统以DSP TMS320LF2407A为处理器,包括一氧化碳传感器模块、温度传感器模块和紫外火焰传感器模块.紫外火焰传感器可以很好地区分闪燃火和阴燃火,一氧化碳传感器和温度传感器能够对闪燃火和阴燃火产生不同的反应,因此系统采用两种不同的算法来探测闪燃火和阴燃火.该火灾探测系统在燃烧室中通过了实验验证.实验表明,该火灾探测系统比通用的感烟型探测器具有更快的探测速度和准确度,且不会在常见干扰源的干扰下产生误报警. 相似文献
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基于概率模型的光纤光栅传感网络优化布置 总被引:1,自引:0,他引:1
光纤光栅传感器相比与传统传感器,其特有的轴向敏感性决定了它的探测距离在传感器的不同方向上是有差异的,因此光纤光栅传感器的布置角度对于传感器网络的性能具有很大的影响。基于传统传感器的概率探测模型,本文提出了一种贴合光纤布拉格光栅传感器实际特点的探测模型,并通过实验验证了其正确性,继而利用这一模型,采用粒子群优化算法进行了光纤光栅传感网络的优化布置。最后,同不考虑布置角度的优化布置方法进行了比较,结果表明,在实际应用中考虑布置角度对于传感网络性能具有很大的提升。 相似文献
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A theoretical study was conducted using a multiple-voltage probe sensor for detecting nonconducting inclusions in conducting media. Results show that the multiple-voltage probe sensor is capable of providing precise quantitative measurements of submerged nonconducting objects if the surface voltage response has a standard two-peak form. The standard response is observed for well-localized non-slender single inclusions below the sensor surface. In this case, the peak separation distance is associated with the inclusion depth whereas the peak magnitude is associated with the inclusion volume. Linear dependencies of the inclusion depth and the inclusion volume are observed for a wide variety of inclusion shapes. The predefined form of the surface voltage response makes it feasible to identify useful signal responses at very high noise levels. This is accomplished by using a 2D neural network classifier, based on the probabilistic neural network. A reasonable recognition error of less than 20 % is obtained if the signal-to-noise ratio is larger than or equal to 1/10. A metal casting example shows that the multiple-voltage probe sensor can measure inclusion concentrations in hot conducting melts (gas bubbles and sludge) with inclusion radii in the range from 100 to 1000 m. In contrast to existing particle counter technology, this sensor construction is simple to construct and does not require special aperture and vacuum treatment. 相似文献
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本文通过对复膜塑编水泥袋防喷灰工艺与设备研究,采用塑料编织袋复膜、裁切、缝制等新技术原理,在裁切设备、复膜、缝制工艺等方面对原产品有明显改进,从而显著提高了产品性能和产品质量,并对以减少包装袋表面渗灰及袋口窜灰问题,改善水泥包装工作环境和减少水泥损失等方面效果显著。 相似文献