共查询到19条相似文献,搜索用时 168 毫秒
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为了提高非色散红外(NDIR,Non-Dispersion Infrared)二氧化碳()气体传感器的标定效率,提出一种针对NDIR单通道气体传感器的高效快速标定算法.首先采集m个传感器节点在不同温度、不同浓度下对应的电压值,然后对于每个节点,将它的数据点(温度,浓度,输出电压)进行曲面拟合。拟合后的曲面作为候选曲面,测量待标定传感器的6个在不同温度、不同浓度下对应的输出电压数据点.选择一个与这6个数据点最优匹配的曲面.以此作为待标定传感器的标定曲面。实验结果表明。算法标定准确性和可靠性高。按照5%+50x的精度,算法标定的数据合格率达到99%。 相似文献
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针对主要烟气污染物气体一氧化氮NO/二氧化硫SO2监测存在的温漂大、温度补偿系统体积大、成本高的问题,采用MEMS工艺,研制了一种三电极碳纳米管传感器阵列。该阵列由三个不同极间距的传感器构成,分别检测NO、SO2浓度及温度。研究了极间距、气体浓度和温度对传感器的影响,分析了传感器对气体浓度和温度的敏感机理。三个传感器在不同的气体浓度、不同的温度下,具有不同的单值敏感特性。传感器重复性好、灵敏度高;阵列可以不分离混合气体,直接检测NO、SO2成分及温度,具有温度补偿的功能,能够用于解决烟气污染物检测在工作温度变化时存在的误报问题。 相似文献
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介绍了国内常用的甲烷传感器及其优缺点,在此基础上设计了一种基于非分光红外法(NDIR)原理的甲烷气体传感器.针对红外探测器输出的特性设计了微弱信号放大电路,使用AD8552对红外热探测器输出的微弱信号进行放大,AD7190对滤波放大后的信号进行采样转换,采用软硬件相结合的方法来减少噪声干扰的影响.通过对不同浓度范围的标准甲烷气体进行实验测量,拟合得到探测器输出的电压差值之比和气体浓度之间的关系.根据得到的曲线和数据分析选择分段插值的浓度计算方法,实现了对甲烷气体进行实时测量的功能.给出该传感器在甲烷体积分数为0%~5.05%的测量结果. 相似文献
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压阻式压力传感器的在线综合补偿 总被引:6,自引:0,他引:6
利用曲面拟合法来建立被测目标参量与传感器输出量之间的对应关系,借助二维标定/校准实验,按最小二乘法原理由实验标定/校准数据计算出均方误差最小时的回归方程中的系数。这样,当测得了传感器的输出值时,就可由已知系数的多维回归方程来计算相应的输入被测目标参数。该算法应用于压阻式压力传感器,在进行温度补偿的同时也进行了非线性校正,使传感器的读数准确度达到0.05%,同时利用传感器自身的RS232接口对其进行在线补偿和校正。 相似文献
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基于非色散红外吸收原理,以电调制红外光源、采样气室和双元红外探测器组成的红外传感模块为核心,利用差分吸收检测技术设计了一种小型化高性能的SF6气体传感器.利用标准气体进行浓度标定,拟合了SF6气体浓度与电压关系曲线,实现了对SF6气体浓度的准确检测.根据传感器检测误差随环境温度变化的规律,系统研究了温度补偿方法,有效提高了传感器在不同温度下的检测精度.实验结果表明,该传感器系统在环境温度10℃~40℃、气体浓度0~2500×10-6范围内的检测精度小于±50×10-6,分辨率为1×10-6,系统响应时间小于5 s,具有良好的重复性和稳定性. 相似文献
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差分吸收光谱法(DOAS)原理简单、检测精度高、响应速度快、可应用于非接触和连续在线监测。本文利用差分吸收光谱法对NH3浓度进行在线反演。不同于传统的DOAS中选取部分波长点光谱数据反演气体浓度,本文充分利用反演波段内所有实验数据,联立超定方程组,并用最小二乘法求解。为了消除温度对反演结果的影响,利用20℃与其他温度下NH3分子数密度比的比值和对应温度的关系拟合出温度补偿函数对反演结果进行温度补偿。实验结果表明该方法反演NH3浓度时具有较高的反演精度。 相似文献
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煤炭自燃是煤矿的主要灾害之一。不仅烧毁宝贵资源,还严重危害井下工作人员的安全与健康。CO2气体灭火可以应用于矿井的防灭火工作。煤矿井下的气体是多种气体的混合物,煤对很多种气体具有吸附特性。运用量子化学理论高斯03软件包对二氧化碳气体在煤表面吸附时,甲烷气体对其吸附能力的影响进行研究。结果表明,当煤表面分别吸附1个和2个CO2分子时,有1个CH4分子存在会促进煤表面吸附CO2分子。但当CO2分子的个数大于2个时,有1个CH4分子存在就会抑制煤表面吸附CO2分子。因此,CH4分子对煤表面吸附CO2分子是有影响的。甲烷气体的含量能够影响煤对二氧化碳气体的吸附。 相似文献
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从抽象的三输入三输出数学模型出发,建立三向力传感器的一般数学模型,对该模型进行一阶泰勒展开并将拉格朗日余项作为误差忽略,得到三向力传感器线性标定计算的正则方程组。分别在3个方向采取单向多次加载,通过最小二乘法将输出与载荷对应的数据进行线性拟合,将拟合结果与原正则方程组比对,确定其系数阵,从而得出标定的算法。该标定方法推导中仅假定传感器3个应变梁正交,同时考虑了三向变形耦合关系,而没有限定传感器的具体结构形式,因而该算法对于不同结构的三向力传感器具有一定的通用性。该算法为多向耦合类型传感器的标定提供了新的思路和研究方法。 相似文献
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This paper describes the development of a gas sensor system to be used as a sensing node to form a dense real-time environmental monitoring network. Moreover, a new auto-calibration method is proposed to achieve the maintenance-free operation of the sensor network. The network connectivity can be used not only for data collection but also for the calibration and diagnosis of the sensors since the measured pollutant concentrations can be easily compared through the network with nearby sensors and governmental monitoring stations. Different pollutant concentrations are usually monitored at different sites. However, a case study on local NO2 distribution has shown that there exists a special condition under which pollutant concentrations become low and uniform in a certain local area. The baseline of the gas sensor response can be adjusted in this special occasion using the pollutant concentration values reported from the neighboring environmental monitoring stations. The experimental result has shown that NO2 concentration can be measured with sufficient accuracy by incorporating appropriate temperature and humidity compensation into calibration curves. Moreover, a case study on auto-calibration demonstrates its effectiveness in keeping the measurement accuracy of the sensor system in long-term operation. 相似文献
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Potentiometric cell, Au/LiCoO2 5 m/o Co3O4/Li2.88PO3.73N0.14/Li2CO3/Au, has been fabricated and investigated for monitoring CO2 gas. A LiCoO2–Co3O4 mixture was used as the solid-state reference electrode instead of a reference gas. The idea is to keep the lithium activity constant on the reference side using thermodynamic equilibrium at a given temperature. The thermodynamic stability of the reference electrode was studied from the phase stability diagram of Li–Co–C–O system. The Gibb’s free energy of formation of LiCoO2 was estimated at 500°C from the measured value of the cell emf. The sensors showed good reversibility and fast response toward changing CO2 concentrations from 200 to 3000 ppm. The emf values were found to follow a logarithmic Nernstian behavior in the 400–500°C temperature range. CH4 gas did not show any interference effect. Humidity and CO gas decreased the emf values of the sensor slightly. NO and NO2 gases affect this sensor significantly at low temperatures. However, increased operating temperature seems to reduce the interference. 相似文献
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In the present work, a conducting polymer, doped polypyrrole, was used to develop a gas sensor by dip-pen nanolithography (DPN). The response time of the sensor to 18 ppm CO2 was 9 s. The sensor response increased linearly as the CO2 concentration increased. A possible mechanism for the CO2 sensing was discussed. 相似文献
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We report a feasibility study of monitoring gases continuously by means of an adapted piezo-optical dosimeter system. The test gas is carbon dioxide whose presence is detected via a pH indicator colour change. Sensing spots consist of m-Cresol Purple supported in a buffered ethyl cellulose matrix and deposited on an indium-tin oxide coated piezoelectric film. The change in absorbance is measured via illumination with an amber LED whose peak emission at 592 nm corresponds to the basic form of the reagent. A sensor was developed and calibrated over the range 0–2.5% CO2 of interest for personal monitoring. The 90% response times are 3–4 min but the response rates could be used to trigger an alarm in the first few seconds of CO2 increase. 相似文献
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The prototype of a CO2 sensor made of CuO–BaTiO3, which has capacitance sensitive effect, is designed based on the pn heterojunctions of CuO and BaTiO3 semiconductors. The preparation of BaTiO3 semiconductor powders is pointed out, using the coprecipitation and semiconducting techniques. The characteristic quantities relating to the capacitance sensitive effect of the sensor are studied systematically with the aid of a gas tester. A reasonable mechanism of the sensor is proposed. 相似文献
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针对载体催化型瓦斯传感器的近似直线形的输出曲线存在非线性误差较大、准确度低的问题,提出了一种采用最小二乘法建立载体催化型瓦斯传感器输出电压与瓦斯体积分数函数关系的方法。以MJC4/2.9J型载体催化元件为实验对象,结合相应的实验数据得到输出电压与瓦斯体积分数的拟合曲线,该拟合曲线的结果表明,采用最小二乘法建立的瓦斯传感器输出电压与瓦斯体积分数函数关系非线性误差较小、准确度高,并将该函数关系应用到瓦斯检测仪的设计中。实际应用结果表明,该瓦斯检测仪具有较高的精度及稳定性。 相似文献
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