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Hybrid suspended gate FET (HSGFET) devices with a sensitive layer of platinum or gold were proven to be well-suited as reproducible ozone detection from the low ppb region up to 500 ppb and higher. Operating at 130°C, gold shows a nearly linear dependence on ozone concentration with high signals and a small humidity influence. Platinum at 130°C convinces with a fast response time and low cross sensitivities to other gases. 相似文献
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平面工艺SnO2薄膜甲醛气敏元件的研究 总被引:1,自引:0,他引:1
用ANSYS仿真软件得到最优化的气体传感器电极结构,采用平面工艺在硅衬底上制作了3 mm×2 mm的直热式Sn02薄膜甲醛气敏元件.用溶胶凝胶(sol-gel)法制备了掺Pd的纳米SnO2薄膜,材料的平均粒径约为15nm.元件的最佳工作温度约为230℃,在该加热温度下测试了元件对体积分数为50×10-9的甲醛气体的灵敏度以及响应恢复时间.实验证明:元件的灵敏度随气体浓度的增大而增大,元件的响应和恢复时间均约为50s. 相似文献
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Gas gap is usually used as an important thermal insulation in micro gas sensors to reduce the heating power. The heat transport through the gap consists of two parts, heat conduction by air and thermal radiation between surfaces. It is usually regarded that thermal radiation through the gap is negligible compared with conductive heat transfer by air. This work investigates the heat transport by thermal radiation and heat conduction through a broad size range of gas gaps from one nanometer to dozens of micrometers. The result shows that thermal radiation is the major way of heat transfer when the gap is less than 20 nm, which will result in unexpected high energy consumption in the process of minimization. The equivalent thermal conductivity of thermal radiation is computed and a partition map is depicted to demonstrate the relative importance of radiation and conduction on different gap scales under dissimilar surface temperatures. A practical gas sensor heated by a micro hotplate (MHP) is thermally analyzed. The calculation shows that extra energy consumption comes forth as the gap distance reduces to several tens of nanometers. 相似文献
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提出了一种基于微机电系统(MEMS)惯性传感器的航姿测量系统。分析了一些传统姿态解算算法融合过程中的不足,提出一种高效的融合算法,利用梯度法将加速度计和磁力计对地球重力场和磁场矢量的观测量去修正陀螺给出的姿态信息。针对实际测量系统中振动对姿态的干扰问题,提出切比雪夫II型低通数字滤波器进行传感器数据预处理,并结合运动状态修正融合算法从而进一步抑制振动。通过实验表明:该系统的算法具有较低的计算负荷,能有效地估计出姿态,抑制振动有害加速度对姿态估计的影响,测量动态误差小于2°,静态误差小于0.8°。 相似文献
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Hollow SnO2 spheres were prepared in dimethylfomamide (DMF) by controlled hydrolysis of SnCl2 using newly made carbon microspheres as templates. The phase composition and morphology of the material particles were characterized by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The gas sensing properties of sensors based on the hollow SnO2 spheres were investigated. It was found that the sensor exhibited good performances, characterized by high response, good selectivity and very short response time to dilute (C2H5)3N operating at 150 °C, especially, the response to 1 ppb (C2H5)3N attained 7.1 at 150 °C. It was noteworthy that the response to 0.1 ppm C2H5OH of the sensor was 2.7 at 250 °C. 相似文献
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Yusuke Arai Michiko NishiyamaKazuhiro Watanabe 《Sensors and actuators. A, Physical》2011,172(2):359-364
Hetero-core fiber optic sensors can transmit sensing and communication signals on a single fiber optic transmission line and have numerous advantages for environmental information monitoring such as home security. Moreover, these sensors are cost effective due to their temperature independence and light-intensity-based measurements. We have previously developed a hetero-core fiber optic binary sensor that can be connected in series to detect the number of doors and windows that are opened or closed. In this paper, we propose an improved method for using hetero-core fiber optic binary sensors that are connected in series, which are referred to as binary switches. A unique pulse loss change enables the states of the connected switches to be identified. As a result, the total optical loss in the transmission line is reduced. Therefore, the number of binary switches connected in series can be increased on a single transmission line. The unique pulse loss peaks can be controlled by the action of a flat spring and by adjusting the position of the flat spring inside the binary switch module. Typical pulse peaks of each binary switch are from 0.13 to 0.75 dB in the positive direction and from −0.47 to −0.03 dB in the negative direction, while the typical insertion loss is from 2.23 to 2.61 dB, depending on the position of the hetero-core segment within the binary switch module. The connection of two binary switches in series is successfully demonstrated for monitoring the optical loss change on a single transmission line. The results of the present study show that the number of binary switches connected in series can be increased significantly on a single transmission line. 相似文献
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The conductance of several tin oxide gas sensitive layers was simultaneously measured in thermo-cyclic and isothermal operation mode at various concentrations of CO and propene in air, respectively. Different measurement conditions were set by the cycle time, the gas flow rate, the humidity and the thickness of the sensitive layer. The sensor response is expressed by the conductance-over-time profiles (CTPs), the gas sensitivity or by the sum of the CTP sampling points. The resultant sensitivities from the CTPs were found to be higher than those of the isothermal measurements. The CTPs considerably change with the kind of gas as well as with the variation of the measurement conditions. This is discussed for both types of target gases with respect to the temperature, the adsorbates assumed and the reaction kinetics in relation to the gas transport conditions in the porous gas sensitive layer. 相似文献
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酞箐气体传感器发展趋势 总被引:1,自引:0,他引:1
酞箐作为一种重要的气体敏感材料,有着良好的应用前景。根据实用的要求,采用了各种方法来改善传感器的气体敏感特性。介绍了酞箐气体传感器发展的趋势,包括加速响应、便于检测和应用、消除基线漂移的影响、提高选择性及微型化和多传感器集成化等方面。 相似文献
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为解决水下传感器的时间同步工作受到节点移动、传播时延高、低能耗等因素影响的问题,提出一种时间同步迭代算法(MV-Sync),充分考虑了节点随洋流运动的问题。利用节点的运动模型与空间相关性进行节点的定位与速度测算,通过信标节点迭代方式完成对所有节点的时间同步工作,推导出时间同步的参数计算方程。仿真结果表明,与现有算法相比,其在同步精度上有一定的优化,更加适用于高密度监测环境。 相似文献
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为准确评测机载防火系统的灭火功能与性能,设计基于微压差测量技术的灭火剂浓度机载测试系统。通过真空泵采集灭火剂与空气复合气体,利用过滤器对其展开过滤后,传输至微压差浓度传感模块,经该模块的气体加热器加热该气体,温度控制器控制所加热气体温度,然后通过节流设备使其形成压差,利用压差传感器变更压差信号为电信号,再应用信号处理器展开信号处理,计算出灭火剂浓度并得出与其浓度值呈正相关的电信号;依据该信号,利用流量恒定设备高精度控制灭火剂与空气复合气体流量,合并该气体流量后将其输入稳压缓冲罐进行缓冲,通过气体分析仪测量灭火剂与空气复合气体差异浓度和压差的关联,输出灭火剂浓度数字信号,并利用排气口将测试完的灭火剂空气复合气体排入真空泵,通过真空泵将测试完的灭火剂空气复合气体排放至空气内。试验表明:该系统的测量范围大、测量数据有效且精准程度高,重复与稳定功能性好,灭火剂体积浓度与维持时长在常温下大于低温下。 相似文献
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为满足数字式光栅测长仪测量精度的进一步提高,设计制作了一套适用于数字式光栅测长仪的高精度多路温度测量系统.系统采用新型数字式温度传感器,将温度量直接转换为数字量,送AT89C52处理.通过AT89C52处理后的温度数值由数码管显示.在保证电路各项性能的条件下,采用了尽可能简单的电路,同时提高了温度测量的精度以及抗干扰能力,且不受电源波动影响.经法定计量部门检定,测量精度达±0.1℃.在同精度的测温仪中,成本相对很低. 相似文献
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提出一种基于新的相位展开算法的人面部非接触式三维扫描系统,可用于活体人睁眼情况下的快速精确面部三维复制。该系统由DIP投影仪投射对人眼无伤害的正弦光栅条纹,使用提出的枝切截断相位展开算法,获取被测人面部的相对光编码信息,然后,投射一幅具有绝对相位的分割线图,通过Hilditch细化算法精确获取分割线图的单像素级绝对相位,从而完成用于三维测量的绝对相位精确获取,最后,在主动视觉测量原理下完成了人面部三维测量重建。为了验证本系统的性能,使用自制测量设备对人的面部进行了测量重建,结果表明:该系统能在1s内完成对人眼无伤害的编码条纹的投射与采集,能满足活体人的面部测量所需的条件。 相似文献