用于；さ缂魈，断绝表界杂质、水汽与碰撞滋扰，结构精密、绝缘性好，保险电极检测与工作状态不变靠得住。

It is used to protect the electrode body from external impurities, moisture and collision interference. With precise structure and good insulation, it ensures stable and reliable detection and operation of the electrode.