将清洗后的试样浸入水中，使试样与水面成垂直，然后移出水面，从倾斜45角方向观察离开水面后的试样表面是否有挂水珠或无水的区域，如果有，钢带表面有污物存在，如果试样表面形成的水膜能均匀地占满全部表面，则说明清洁度高。
Water cut-off method for production process of galvanized strip:
Immerse the cleaned sample in the water, make the sample perpendicular to the water surface, and then move out of the water surface. Observe whether there is water drop or no water area on the surface of the sample after leaving the water surface from the inclined 45 angle direction. If there is dirt on the surface of the steel strip, if the water film formed on the surface of the sample can evenly occupy all the surfaces, it means that the cleanliness is high.
