电磁水表电极极化及工艺原理

Electrode Polarization and Process Principles of the Electromagnetic Water Meter

电磁水表中,由信号电极引入的极化干扰使得小流量下信噪比难以提高,限制了测量范围的拓展。极化干扰主要来自电极体材料差异和电极表面效应,包括化学和电化学极化现象。探究极化原理对电极工艺的理解和设计有重要的指导意义。以不锈钢电极为研究对象,指出极化电势的产生主要与钝化效应有关,解释了其受pH值和温度等环境影响的原因在于钝化膜的失效。提及一种电极加工工艺实施的原理及效果,不锈钢电极工艺除机械加工和研磨抛光外,增加高温退火和酸洗,可满足信号电极对表面及体材料的要求。

In the electromagnetic flow sensor, the interference introduced by the signal electrodes makes it difficult to increase the signal-to-noise ratio in the state of small flow, which limits the expansion of the measurement range. The electrode interference mainly comes from electrode body material differences and surface effects, including chemical and electrochemical polarization. Exploring the principle of polarization has important guiding significance for the understand-ing and design of the electrode process. The paper takes stainless steel electrode as the research object, and points out that the polarization potential is mainly related to the passivation effect, explaining that the environmental influence of pH and temperature is due to the failure of the passivation film. The principle and effect of an electrode processing process are mentioned. In addition to mechanical processing and grinding and polishing, the high temperature annealing and pickling processes are applied to meet the requirements of the signal electrode on the surface and body material.