共查询到19条相似文献,搜索用时 46 毫秒
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新型电容式湿敏元件性能检测采用下位机采样,上位机处理数据的方式。该套装置克服了以往托测试的诸多不便,节约时间,可实现批量测量,适用于电容式湿敏元件折参数测试及可靠性试验过程中的监测,是研究电容式湿敏元件的有力工具。 相似文献
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MgCr_2O_4—SnO_2烧结体湿敏半导体陶瓷具有微孔结构。合理地选取配方,可使温度系数α_T极小。由这种湿敏元件组成的湿度传感器采用微孔结构的RuO_2电极和加热清洗装置,底座上还设置了导电环。解决了空气中油蒸气、尘埃等侵入引起的污染问题,延长了传感器使用寿命,保证了测湿精度。这种湿度传感器配用数字式湿度测控仪,可实现数字测湿。为高温环境中测湿控湿提供了新的测试手段。文中引用了计量部门的测试标定报告,说明这种湿度传感器及数字式湿度测控仪的性能和技术数据。 相似文献
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介绍了一种新型Li_2SnO_3厚膜湿敏元件。用X-射线粉末衍射图和电子能谱分析了该湿敏元件感湿体的组成和价态。由这种材料的物理机制和极化机制,建立了等效电路模型。用复阻抗分析法分析了感湿机理并得出如下结论:(1)晶界表面电阻随相对湿度上升而下降,是主要敏感部分。(2)导电载流子不只是氢离子或水合氢离子而且还有锂离子。(3)在高湿下存在电解质电导。 相似文献
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采用水热腐蚀铁钝化法在单晶硅片上生长铁钝化多孔硅(IPS)薄膜,以IPS为感湿介质制成湿敏元件。在不同湿度环境以及测试频率下,测出其电容值,得到了IPS的湿敏特性曲线。研究发现,当相对湿度从11%RH逐渐增加到95%RH的过程中,在测试频率为100Hz时,IPS湿敏元件的电容值增大幅度达1500%,电容响应时间在升湿过程和脱湿过程分别为15s和5s,并且IPS湿敏元件的温度系数在15℃到35℃的范围内较小。结果表明:IPS湿敏元件的特性包括灵敏度、响应时间以及温度系数等均优于多孔硅(PS)湿敏元件的特性。 相似文献
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高分子电阻型湿敏元件经适当的交流电激励老化后,前后的电阻值和长期跟踪测试其性能变化.结果表明,被适当的交流电处理的湿敏元件的感湿特征量的线性和长期稳定性变好了. 相似文献
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A. ErolAuthor Vitae S. OkurAuthor VitaeN. Ya?murcukarde?Author Vitae M.Ç. Ar?kanAuthor Vitae 《Sensors and actuators. B, Chemical》2011,152(1):115-120
The humidity-sensing properties of ZnO nanowires synthesized by carbothermal catalyst-free vapor solid (VS) technique were studied. The morphology and the crystal structure were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The humidity adsorption and desorption kinetics of the synthesized ZnO nanowires were investigated via quartz crystal microbalance (QCM) measurements. The observed positive frequency shift of ZnO nanowires when loaded on the QCM crystal under varying relative humidity conditions can be explained in terms of visco-elastic variations in their mechanical stiffness. 相似文献
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李炳成 《计算机测量与控制》2002,10(3):208-210
文章通过测定季铵化聚苯乙烯共聚物类湿敏元件的湿敏特性,根据Arrhenius关系和大量测试数据的分析,导出了该湿敏元件的电阻随着相对湿度变化的半经验公式,并通过实例应用该半经验公式。 相似文献
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Chang-Dong Shen-Liang Hui Carlo U. Joseph R. 《Sensors and actuators. B, Chemical》1997,40(2-3):217-222
Nafion, sol-gel derived SiO2 and SiO2/Nafion composite films were prepared through casting and dip-coating methods. Impedance response of the films to relative humidity and the stability of the response against different aging environments were examined. The response to relative humidity of each film was analyzed with their complex impedance spectra at different humidities. 相似文献
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Optimisation of the number of required measurement points and their location is an important research topic in sensor networks. Finding the optimal positions increases spatial coverage and reduces deployment costs. This paper presents an approach for the case that two attributes have to be measured with a different number of available sensors. The proposed cokriging method performs cross-attribute fusion in sensor networks by being based on the analysis of multi-variable spatial correlations. To the best of our knowledge, this scientific work is the first one considering kriging and cokriging interpolations as IF methods. The single-variable ordinary kriging and bi-variable methods were applied to experimental data. The combination of humidity and temperature data in a refrigerated container is used as exemplary case, humidity measurements are considered to be the expensive attribute to measure. The average estimation error for intermediate points was estimated as a function of the number of humidity sensors. When variability is high, data fusion using the bi-variable method produced results as accurate as the single-variable one, without the necessity of deploying a large number of humidity measuring points, by complementing the estimation with temperature measurements. 相似文献
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This paper defines a discrete time dynamic model of a passive air-conditioning unit with respect of environmental conditions, for micro-climate in growth chambers and greenhouses, where temperature and relative humidity evolve and should be controlled independently. As the analytical model developed turned out to be complex, highly nonlinear and difficult to use for control objectives, especially with respect to relative humidity, a Takagi–Sugeno MIMO structure was used to model nonlinearities of the unit. Two structures (a global and two levels) identification algorithms were implemented. Pseudo-Random Multi-level Signals were used as excitation input in order to capture the dynamics and nonlinearities and to cover a wide range of inputs in which the air-conditioning unit will operate. The consequent parts of the relative humidity contained additional inputs composed of the increments values of the control inputs. Identification and validation results using the two levels showed good prediction performance for the temperature and the relative humidity outputs despite their strong coupling. 相似文献
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