摘要
本实验用8mol%Y_2O_3-ZrO_2固体电解质制成了极限电流型氧传感器,并测定了氧在0.23～28.70mol%,温度在550～800℃范围时,传感器的输出特性,观察到该传感器有较好的稳定性和电压电流特性曲线。实验验证了极限电流值与氧摩尔分数和温度的关系。
A new type of oxygen sensor for oxygen concentration determination in exhaust gas is studied experimentally in this paper. This new oxygen sensor contains of two portions which act as electrochemical cells. One portion is called the pump cell while the other is called the sensor cell. When the sensor is attached to an external power supply(E), oxygen in the cavity is drawn by the current(Ⅰ) in the pump cell to the atmosphere to produce an oxygen concentration gradient, so that the oxygen molecules in the atmosphere diffuse to the cavity through the diffusion hole. As a result of the pumping action. an EMF (=(RT/4F)ln(Po＇_2/Po″_2)) develops across the sensor cell which, can be used to measure the change in partial pressure of oxygen in the cavity relative to that in the atmosphere. When the applied voltage is adequate, oxygen diffusion from the atmosphere to the cavity is a measure for rate-controlling, then the pumping current reaches to the ultimate value which is proportional to the logarithm of the oxygen molar fraction in the atmosphere.In this paper, the repeated ultimate current related to the oxygen molar fraction is observed with oxygen concentration from 0.23mol％ to 28.70mol％ and a temperature range of 550℃～800℃ in an O_2-N_2 gas mixture. Results of this investigation show that relationship between the ultimate current and two factors influencing the limiting current,oxygen molar fraction and temperature,is in good agreement with what is expected theoretically. The other factors, including gaseous diffusion coefficients, the total pressure and the two geometric parameters (area and length) of the gas diffusion hole are considered theoretically in the normal diffusion region.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
1992年第3期262-266,共5页
Journal of The Chinese Ceramic Society
关键词
氧化锆
氧传感器
氧扩散
气体定氧
zirconia
oxygen sensor
oxygen determination
oxygen diffusion
