Lenses are important optical components of laser tubes, as they can directly affect output power and quality of laser beam. Therefore, maintenance of the lenses is necessary for keeping laser tubes working properly. The maintenance requirements are shown below:

1. Lenses shall be wiped by cotton swabs with absolute ethanol (alcohol) once or twice every month. If the laser tubes are used in smoky or dusty environment, additional wipes shall be implemented.
2. The lenses shall be wiped when their temperature has dropped to room temperature. Wiping the lenses when the temperature is still high may cause breakage of the lenses or damage on the lens surfaces.
3. When the lenses surfaces are dirty, do not wipe the lenses too hard.Instead, users can soak the lenses in absolute ethanol (alcohol) for 10-20 minutes and wipe them with cotton swabs. The swab sticks shall not directly contact the lenses as they may damage the lens films.
4. The ethanol shall be completely volatilized before the laser tubes are turned on. Ethanol remained on the lenses is easily to burn when the laser tubes are turned on, resulting in breakage of the lenses or damage on the lens surfaces.
5. There shall be no moisture, frost, ice or water on the lenses. When such situations occur, users shall clean the lenses first before turning on the laser tubes. Forced operation of the laser tubes without cleaning the moisture, frost, ice or water may cause damage or breakage of the lenses.
6. To avoid condensation, frosting and icing on the lenses, the difference between cooling-water temperature and room temperature shall not be significant. The temperature difference shall be controlled within ±5°C (-5°C in summer, +5°C in winter).
7. Dual-lens laser tubes are equipped with anti-dust lenses. When the laser tubes are working, the anti-dust lenses shall be installed on the laser tubes to reduce the pollution of the lenses from smoke and dust.