In welding operations, in order to protect the safety of the operator, the protective lenses generally need to be replaced once (8) hours of cumulative use. The main hazards of welding operations include metal smoke, toxic gases, arc light, etc. To prevent welding eye damage, you must wear a mask for protection. The protection of welding glasses is relatively limited and can only be used by auxiliary workers in the welding area. Due to the strong visible light and large amounts of invisible ultraviolet rays produced during welding, they have a strong irritating and damaging effect on human eyes. Long-term direct exposure can cause eye pain, photophobia, tears, fear of wind, etc., and can easily cause eye conjunctiva and Inflammation of the cornea (commonly known as electrooptic ophthalmia).

When the welded part of the workpiece heats up to the welding temperature, the solder wire is fed and comes into contact with the solder joint of the workpiece to melt and moisten the solder joint. The solder should contact the weldment from the opposite side of the soldering iron.

The amount of tin supplied should be appropriate. Generally, it is better to have a uniform and thin layer of solder that can fully wet the entire solder joint. Qualified solder joints should have a conical shape, no tail, slightly concave surface, and metallic luster. The lead outline can be vaguely distinguished from the solder joints.

If too much solder accumulates, some hidden defects may be hidden inside, and the strength of the solder joint may not be high; but if too little solder is filled, the entire solder joint cannot be completely wetted.