测量油品含水量的电容式传感器机理

电容式传感器利用油与水介电常数差别较大的特性,可测出油品中水的质量分数。从物质分子结构的特征出发,探讨传感器的工作原理,分析在交变电场作用下水与油的极化过程以及交变电场频率对极化强度的影响。得出在交变电场频率为10MHz 时,油与水的介电常数差别最大,因而将10MHz 作为传感器的工作频率,可获得最高灵敏度。
关键词: 位移极化; 取向极化; 中性; 极性; 电荷密度
Abstract : The capacitive sensor can measure the mass fraction of water in oil through the great different of di2 electric between oil and water. The mechanism of capacitive sensor and the polarizing process of water and oil in alternating electric field and the influence frequency on the strenth of polarization is discussed depart from molecule structure. At the same time it will be pointed out that the difference of dielectric between oil and water is the greatest when the frequency of alternating electric field is 10 MHz. Therefore if the working frequency of
the sensor is 10 MHz ,it can attain the highest sensibility.
Key words : movement polarize ; orient polarize ; neuter ; polarity ; charge density