dipping coil primary meana

例句：

1. 1. The dipping coil is used to clean the surface of the metal before it is soldered.
   浸入式线圈用于在焊接前清洁金属表面。
2. 2. The primary medium in this process is water, which helps to dissolve the paint.
   在这个过程中，主要介质是水，它有助于溶解油漆。
3. 3. The dipping coil was designed to improve the quality of the printed circuits.
   浸入式线圈被设计用来提高印刷电路板的质量。