Development of ACM Sensor for Aggressive Ions in Rain

研究了由锌与铂偶联组成的ACM传感器用于酸雨pH测量的可能性。用[SO_4^ ]：[NO_3^-]= 2：1的H_2SO_4/HNO_3溶液制备了不含海盐的人工酸雨<2->。用去离子水稀释H_2SO_4-HNO_3溶液，使pH值在3 ~ 5.5之间。测定了铂和锌在流动人工酸雨中的极化曲线。系统地研究了传感器结构和人工酸雨流量对传感器耦合电流的影响。传感器输出IG取决于阴极面积而不是阳极面积，并且随着阳极和阴极之间的距离的减小而增加。基于上述结果确定传感器的配置。由此可见，IG主要取决于人工酸雨溶液的pH值和电导率，当大于10 mm/s时，与流速无关。因此，可以通过测量和分析具有不同配置的多个传感器的输出来现场监测实际雨水的pH值和电导率。在此基础上建立了校正方程，并对实际降雨进行了pH监测。

The possibility of ACM sensor, which is composed of plantinum coupled with zinc, used on the pH measurement of acid rain was investigated. Artificial acid rain without sea salt were prepared with H2SO4/HNO3 solution with [SO_4^<2->] : [NO_3^-] ratio of 2 : 1. The pH range from 3 to 5.5 was obtained by diluting the H_2SO_4-HNO_3 solution with deionized water. The polarization curves of platinum and zinc in flowing articial acid rain were detected. The influences of sensor's configuration and flowing rate of artificial acid rain on the couple current of the sensor were also systematically studied. The sensor output, Ig, depends on cathode area rather than anode area, and increases with decreasing the distance between anode and cathode. The configuration of the sensor was determined based on the above results. It can be seen that Ig mainly depends on pH and conductivity of the artificial acid rain solution, and does not depend on flowing rate when it is larger than 10mm/s. Thus pH and conductivity of the actual rain can be monitored in-situ by measuring and analyzing the outputs of several sensors with different configurations. The calibration equation was established based on above results, and pH of actual rain was monitored.