丝网印刷技术在平板式汽车氧传感器制作中的应用

平板式汽车氧传感器在节能环保中担任着重要的角色。将丝网EBSU技术应用到平板式汽车氧传感器的制作中已经得到认可。本文将结合本课题组的研究对制作平板式汽车氧传感器时丝网印刷的各种参数做简单介绍。     

平板式氧传感器温度场与应力场的数值模拟

对平板式氧传感器的温度场和应力场进行了模拟。温度场的结果显示,锆板在10 s左右前端温度就可以达到均匀,且厚度方向表现出了很好的温度一致性;应力场的结果显示,应力的较大值发生在固定位移与自由端的交界部分。并对平板式氧传感器的印制和装配给出了建议。     

平板式ZrO2汽车氧传感器制备工艺新进展

汽车氧传感器是电喷汽车三元催化转化必不可少的元件,而平板式氧化锆氧传感器是一种新兴的汽车氧传感器。本文讨论了目前国内平板式汽车氧传感器制备工艺的研究进展以及存在的问题,分别对流延成型、丝网印刷、叠成热压和烧结等工艺进行了总结和分析。     

汽车氧传感器保护层性能改进研究

多孔保护层是平板式汽车氧传感器的重要功能层,直接关系到其能否长周期稳定的工作。通过改进已有汽车氧传感器多孔保护层的制作工艺和成分,结合丝网印刷技术,提高保护层的性能,并提出改进保护层的方式和途径。     

Pt/LaF3敏感膜MIS型固态氧传感器研制

研究了可在室温下工作，且具有Ｐｔ／ＬａＦ３敏感膜的ＭＩＳ型固态氧传感器，讨论了它的敏感机理，测试并分析了传感器的响应特性。     

汽车用氧传感器de研究与进展

汽车尾气中的有害物主要有CO、HC、NOx、SOx以及一些微粒物质,给人类赖以生存的大气环境带来了严重的危害.用氧传感器对汽车发动机的空燃比进行调节,控制发动机中的燃烧过程,可以达到减少污染和节约能源的双重目的.目前适用于汽车空燃比控制的传感器主要有三种:氧化物半导体型(TiO2传感器)、浓差电池型(ZrO2氧传感器)、极限电流型.本文在介绍了这三种汽车用氧传感器的原理、结构的基础上,重点介绍了一种新型极限电流型氧传感器一致密扩散障碍层极限电流型氧传感器,并简要分析了其发展趋势.     

薄膜型氧传感器特性及应用

本文介绍一种薄膜型氧传感器,该传感器主要用于汽车尾气排放监测,具有较好的特性与结构,对汽车工业向环保型方向发展有积极意义。     

氧传感器的原理与进展

本文对氧传感器的重要性及氧传感器的种类，工作原理，特点做了详细的阐述，并对氧传感器的发展动向作了进一步论述。     

微型Clark氧传感器的进展

氧传感顺是最重要的化学传感器这一。它与生物酶固定技术相结合可制成多种生物传感器。由于集成电路工艺和微机械加工技术的发展，Ｃｌａｒｋ氧传感器的微型化已取得了突破性的进展。本文对这一进展作了综述。     

汽油Mn杂质对氧传感器特性的影响

氧传感器是闭环控制的汽车发动机电系统的核心部件之一。利用氧传感器检测汽车尾气成分,调节空燃比,可以获得较高的汽油燃烧效率和较好的三元催化系统的净化效率。使用过程中,汽油中的杂质会影响氧传感器的性能。试验研究了汽油中Mn杂质对氧传感器性能的影响。结果表明：Mn杂质严重影响氧传感器的性能。Mn杂质沉积在传感器表面,与铂电极发生反应,导致传感器失效,从而导致排放尾气的净化率降低。     

基于LabVIEW的高效氧传感器检测系统开发

为了实现批量的氧传感器的高效下线检测,设计了一种基于LabVIEW的氧传感器检测系统。该方案采用按设定好空燃比变化规律循环的电控单元(ECU)控制发动机运行,其产生的尾气用来同时检测一组氧传感器。LabVIEW获取ECU的空燃比变化规律同时控制单片机AD采样获得到的各氧传感器的输出信号,通过实时处理获得的数据将得到一系列的氧传感器性能参数。当判断所有参数测量完后,LabVIEW将自动停止测量过程。通过用户自定义且可标定的评价标准,软件将直接给出每只所测氧传感器的性能评价结果。实验结果表明:该系统可以准确快速地检测出氧传感器的各种性能指标,包括起燃激活时间、稀浓信号大小、稀浓响应速度等。     

卟啉传感器研究进展

卟啉类化合物因为光敏性好、性能稳定、易于修饰,采用紫外、红外、荧光、磷光、拉曼等光谱技术和电化学方法都可以检测到它的微小变化,成为传感器研究的理想模型化合物。介绍了卟啉氧传感器、卟啉二氧化碳传感器、卟啉氯化物传感器、卟啉生物传感器和卟啉其他传感器的研究进展,提出了卟啉传感器的发展方向。     

Ratio measurements in oxygen determinations: wavelength ratiometry, lifetime discrimination, and polarization detection

In this work we present ratiometric measurements of oxygen concentrations using a dual-emitting dye. Three different methods for ratio measurements in oxygen sensing are employed. The standard wavelength-ratiometric approach is simple to implement, but the sensor response has significant non-linearity. The frequency discrimination of the lifetimes allows for measurements of dual-emission ratio through a single emission filter. In this case the Stern–Volmer plots are linear. Another option is to use emission polarization.     

电化学氧浓度传感器在环境压力变化情况下的补偿测试技术

电化学氧浓度传感器在测量环境压力变化后就无法准确地测量该环境的氧气浓度.通过理论分析和实验得到电化学氧浓度传感器测量值随环境压力变化的规律,采用该规律对氧浓度传感器进行补偿后就能够得到压力变化环境下的准确氧浓度值.     

Temperature compensation of fluorescence intensity-based fiber-optic oxygen sensors using modified Stern–Volmer model

In practical sensing applications, temperature effects are of particular concern, and hence it is necessary to develop the means to correct the fluorescence intensity measurement in accordance with the working temperature. Accordingly, this study develops a modified Stern–Volmer model to compensate for the temperature drift of oxygen concentration measurements obtained using fiber-optic sensors. The oxygen sensors considered in this study are based on teraethylorthosilane (TEOS)/n-octyltriethoxysilane (Octyl-triEOS) or n-propyltrimethoxysilane (n-propyl-TriMOS)/3,3,3-trifluoropropyltrimethoxysilane (TFP-TriMOS) composite xerogels doped with platinum meso-tetrakis(pentafluorophenyl)porphine (PtTFPP).

The experimental results are fitted to the modified Stern–Volmer model in order to compute suitable values for a temperature compensation coefficient at different working temperatures. It is found that the proposed temperature compensation method reduces the difference in the oxygen concentration measurement for working temperatures in the range of 25–70 °C as compared to data without compensation. The linearity and sensitivity of PtTFPP-doped n-propyl-TriMOS/TFP-TriMOS sensor are better than PtTFPP-doped TEOS/Octyl-triEOS sensor for working temperatures in the range of 25–70 °C.

The proposed approach could provide a straightforward and effective means of improving the accuracy of fiber-optic oxygen sensors if a variable attenuator is designed according to the temperature compensation coefficient. Thus, the fiber-optic oxygen sensor with a variable attenuator could work in a broad temperature range without using a temperature sensor.     

用铈锆固溶体制备新型氧浓差型氧传感器

利用氧化铈—氧化锆固溶体储氧材料的储氧特性,使其作为固态氧分压参考层,制备了一种新型的用于监测汽车尾气排放的氧浓差型氧传感器,克服了传统浓差型氧传感器制作工艺复杂、成本高、不便于微型化的缺点。该传感器结构由钇稳定的氧化锆电解质、氧化铈—氧化锆固溶体氧分压固态参考层和铂电极组成。利用N2和O2的混合气体来模拟尾气对其分别在工作温度350,400,450℃进行测试,发现在空燃比为1附近电势发生突变,突变电势范围为520~-100mV。     

极限电流型氧传感器热力学分析及结构优化

阐述正面开孔氧传感器的结构机理,并对特定结构的氧传感器进行了电热耦合分析,进而利用特定环境下传感器尺寸的仿真设计规律,对敏感芯体结构进行优化设计,并分析不同结构参数的敏感芯体热性能,优化敏感芯体的工作形状.对比电热耦合数值仿真分析与优化后的氧传感器测试结果,研究分析表明:施加2.2W加热功率即可使氧传感器达到400～500℃的工作温度;特定工况环境下,对传感器封接层和敏感芯体厚度的多目标优化设计结果稳定、方法可靠.     

计算机模拟优化的葡萄糖传感器阵列

介绍一种可植入的葡萄糖传感器阵列的设计和计算机模拟优化。葡萄糖传感器采用固定葡萄糖氧化酶层的氧电极和氧参比电极。考虑到葡萄糖传感器的使用寿命，本设计采用氧电极阵列。用计算机对氧电极阵列的氧电极排列的间距和相互影响进行了计算机模拟优化。考虑到葡萄糖传感器在体植入环境的氧浓度较低，而葡萄糖浓度较高，所以采用特殊的膜的结构，以提高葡萄糖传感器的测量范围，并用计算机模拟优化了膜的结构尺寸。     

Novel solid-state manganese oxide-based reference electrode for YSZ-based oxygen sensors

Various Mn-based oxides have been screened to find a suitable all-solid-state gas-insensitive reference-electrode (RE) for yttria-stabilized zirconia (YSZ)-based potentiometric oxygen sensor. The experimental observation of tubular YSZ-based sensors attached with each of the outer Mn-based oxide sensing electrodes (SEs) and the inner Pt-RE revealed that Mn₂O₃-SE was insensitive to all gases including oxygen at operating temperatures below 550 °C. Thus, the planar-like rod-type YSZ-based sensor using Pt-SE, Au-SE and Mn₂O₃-RE was then fabricated and its sensing performances were evaluated at 550 °C. As a result, the planar sensor using a couple of Pt-SE and Mn₂O₃-RE exhibited excellent responses to oxygen in the concentration range of 0.05-21 vol.% obeying Nernst equation and gave negligible responses to other co-existing gases. Close similarity of the results for tubular and planar sensors operated in a wide range of air/fuel (A/F) ratio indicated that the tubular YSZ-based sensor using the inner Pt-RE could be successfully miniaturized to the planar one using Mn₂O₃-RE without sacrificing its performance.     

Millisecond-order response measurement for fast oxygen gas sensors

A novel method for the evaluation of fast response of oxygen gas sensors in terms of milliseconds is developed. Using the method of modulating oxygen partial pressure by changing the total pressure inside the test chamber, the millisecond-order measurement was succeeded. For the 100 Hz sign-wave operation, the measurement system generated the pressure changes from 180 to 220 kPa, corresponding to the change of oxygen partial pressure from 36 to 44 kPa. Using both jump-method and pressure modulation method, the response of the resistive oxygen sensors of cerium oxide thick films were evaluated at 1173 K and the kinetic mechanism of gas sensing was discussed. Their response times of t₉₀ obtained by square-wave change were measured to be 37 and 22 ms for high-to-low oxygen partial pressure and vice versa transition, respectively. The log–log plot of resistance of sensor and the frequency, pressure modulation spectra, was also evaluated at the same time and the kinetics of oxygen sensing was suggested to be diffusion-limited.