共查询到19条相似文献,搜索用时 714 毫秒
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随着工业的快速发展,对温度检测和控制日益严格,温度传感器已无法跟上人们的需求,通过优化湿度传感器的表面结构和对感湿材料微孔设计提高了感湿特性,增强感湿材料的感湿特性,并对湿度传感器测量电路进行改进,提高微小电容测量,设计湿度测试系统。通过实验验证了改进后的湿度传感器测量效果更优越。 相似文献
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基于微波谐振腔汽轮机内流动湿蒸汽湿度的测量原理,分析了微波谐振腔及同轴线小环耦合的场结构分布,设计出两端带栅网结构的湿度传感器.采用HFSS型微波软件对湿度传感器进行了建模仿真,由此得到场分布及S参数曲线图,以此设计出湿度传感器的结构尺寸.仿真结果表明,该微波谐振腔传感器工作在TE011模式下,谐振频率为9.58 GHz,其Q=1 198,适合作为测试流动湿蒸气的传感器.与采用矩形波导和谐振腔的孔耦合相比,这种新型同轴线耦合装置体积小,对汽轮机设备的开口也小,实用性也强. 相似文献
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传统湿度传感器制造工艺复杂、需有线连接信号,对此,文中提出一种纸基无芯片射频识别(Radio
Frequency Identification,RFID)湿度传感器。为提升传感器谐振特性,选择非对称开口环内部分布式加载金属碎片作
为传感器结构,聚乙烯醇(PVA)作为湿敏材料,使用遗传算法和HFSS 射频仿真软件来设计并优化传感器结构。以
喷墨打印技术制作传感器样品,采用滴涂法在传感器表面分别制备了5%、10%、15%三种质量浓度比的PVA 薄膜。
湿敏特性仿真及测试结果一致表明:PVA 与纸基底协同作用可显著提高传感器灵敏度。随PVA 浓度增加灵敏度增
加,15%PVA 传感器灵敏度最高,高湿灵敏度达到12. 22 MHz/ %RH,但随PVA 浓度增加恢复特性变差,5%PVA 湿度
传感器具有良好的恢复特性,恢复度达83. 87%。通过长期多次实验验证了PVA 纸基湿度传感器具有良好的温度稳
定性与中长期稳定性。与同类研究成果对比,文中设计在感湿范围及灵敏度方面有优势且制造工艺更简单,为低成
本湿度传感器的大规模使用提供了可能。 相似文献
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The porous polysilicon capacitive sensor used for measuring relative humidity has the advantages of low cost, ease of fabrication and CMOS compatibility. However, the capacitance of the sensor, which is a function of concentration of water vapour, also depends on ambient temperature. Thus, variation of ambient temperature causes error in the performance of sensor outputs. In this paper, two ANN models have been developed. The first model is used to simulate the behavior of the capacitive humidity sensor (CHS). This model can also be used for on line monitoring of the fault of the sensor. The second model is based on inverse modeling, which can be used to compensate the effect of ambient temperature error. It is found from the simulation studies that the error of the direct model is within ±2% of full scale and for the inverse model the error is within ±0.5% of full scale over a temperature range from 20 to 70 °C. A hardware implementation scheme for realization of the CHS model is also proposed. 相似文献
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《Microelectronics Journal》2003,34(9):865-875
A novel parametric model of a polymeric chemoresistor is proposed for application in the design and simulation of smart gas sensors. The model has been implemented using Cadence™ software and enables the simulation of both the static and dynamic response of a chemoresistor to a mixture of different gases. It also takes into account parametrically the effects of ambient temperature, humidity and sensor noise. The layout design and a schematic symbol have also been generated in Cadence -thus creating a resistive polymeric cell that can be used in the general design of smart ASIC based systems. The top cell comprises several sub-cells allowing versatility and adaptability in implementation through its modular structure. By changing the values of the simulation parameters and/or the mathematical model of the sub-cell that evaluates the gas sensor response, it is possible to extend its application to the design and simulation of chemoresistors in different configurations and with different gas sensitive materials. Here we illustrate our model in the design and simulation of resistive sensors employing carbon-black polymer composite films as the class of gas sensitive material. 相似文献
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研制了一种无湿敏材料的纺织基底无芯片RFID 湿度传感器用于检测环境湿度。通过射频仿真软件
HFSS,获得谐振频率在2. 45 GHz 具有较高品质因数的纺织基底谐振器模型,对以谐振频率偏移量作为灵敏度指标
的检测原理进行了仿真。利用丝网印刷工艺和刻绘工艺分别在不同类型纺织物上制作了无芯片RFID 湿度传感器,
系统研究了制作工艺、纺织品类型和厚度对传感器湿敏特性的影响。结果表明,0. 5 mm 厚度下不同基底类型湿度传
感器的灵敏度由高至低依次为:棉基底、亚麻基底、聚酯纤维基底,恢复特性呈相反顺序,其中棉基底传感器在高湿
范围内平均灵敏度达3. 8 MHz/ %RH,聚酯纤维基底传感器恢复度达86%;相同类型的棉纺织基底下基底厚度越大,
平均湿度灵敏度越高,恢复特性越差。传感器稳定性测试表明传感器具有较好的中长期稳定性。对纺织基底湿度
传感器的感湿机理进行了分析,纺织纤维中的亲水基团与水分子间形成氢键,改变了基底的介电参数,传感器的湿
敏特性与组成纺织品的纤维成分、纤维细度、编织方式有关。 相似文献
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Kh.S.Karimov Kuan Yew Cheong M.Saleem Imran Murtaza M.Farooq Ahmad Fauzi Mohd Noor 《半导体学报》2010,31(5)
A thin film of blended poly-N-epoxypropylcarbazole (PEPC) (25 wt.%),nickel phthalocyanine (NiPc) (50 wt.%) and ZnO nano-powder (25 wt.%) in benzene (5 wt.%) was spin-coated on a glass substrate with silver electrodes to produce a surface-type Ag/PEPC/NiPc/ZnO/Ag capacitive and resistive sensor.Sensors with two different PEPC/NiPc/ZnO film thicknesses (330 and 400 nm) were fabricated and compared.The effects of humidity on capacitance and resistance of the Ag/PEPC/NiPc/ZnO/Ag sensors were investigated at two frequencies of the applied voltage:120 Hz and 1 kHz.It was observed that at 120 Hz under humidity of up to 95% RH the capacitance of the sensors increased by 540 times and resistance decreased by 450 times with respect to humidity conditions of 50% RH.It was found that the sensor with a thinner semiconducting film (330 nm) was more sensitive than the sensor with a thicker film (400 nm).The sensitivity was improved when the sensor was used at a lower frequency as compared with a high frequency.It is assumed that the humidity response of the sensors is associated with absorption of water vapors and doping of water molecules in the semiconductor blend layer.This had been proven by simulation of the capacitance-humidity relationship. 相似文献
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研究了以聚酰亚胺为湿敏材料的光纤Bragg光栅(FBG)湿度传感器并用其对质子交换膜燃料电池(PEMFC)停机过程中内部湿度进行了实时监测。传感器利用聚酰亚胺的湿膨胀效应,实现 了对24.7%- 98%RH范围内相对湿度的监测。采用腐蚀光纤包层的方法减小光纤包 层直径,实验结果表明,该方法能在 不影响FBG相对湿度传感器灵敏度的情况下,提高对外界环境相对湿 度变化的响应速度。所 研制的FBG 相对湿度传感器灵敏度能达到3.8 pm/RH,线性度达到99.85%,最大回程误差不超过9pm,当环境相对湿 度从50%突变到85%时,经过腐蚀处理后的FBG 相对湿度响应时间仅为15.4 s。将该FBG湿度传感器布置 于PEMFC内部进行停机过程中湿度的实时监测,实验结果表明,所制作的FBG湿度传感器能够 准确地反映PEMFC停机吹扫过程中内部湿度的变化。 相似文献