Novanta v30, Руководство пользователя, Страница: 46 / 101

BEAM DELIVERY OPTICS PAGE | 46
Optics are fragile and must be handled carefully, preferably by the mounting ring only. Be careful to
select optics that are thick enough to withstand the maximum assist gas pressure available for the
process. This is especially important in metal cutting applications using high-pressure assist gases.
Cleanliness is another important issue affecting performance and becomes increasingly important as
laser power increases. Dirty or scratched lenses will underperform, exhibit a vastly shortened lifetime,
and may fail catastrophically.
When the application requires air (instead of nitrogen) as an assist gas, use only breathing quality air
available in cylinders from a specialty gas supply company. Compressed shop air contains minute par-
ticles of oil and other contaminants that will damage optical surfaces. If compressed shop air is the only
choice available, it must be filtered and dried to ISO 8573-1:2010 Class 1, 2, 1 specification as shown in the
following table.
Table 3-1 Assist gas purity specifications
Assist Gas
Typical Purpose Specification
Air
Cutting/Drilling Breathing
Grade
> 99.9996% purity; filtered to ISO Class 1
Particulate leverl
Air
Cutting/Drilling Compressed
Instrument-grade air filtered and dried to ISO 8573-
1:2010 Class 1, 2, 1 (< 10 1.0– 5.0
μ
m particles/m3; < –40
°F dew point; < 0.01 mg/m3 oil vapor)
Argon
Welding High Purity Grade
> 99.998% purity; filtered to ISO Class 1 particulate
level
Helium
Welding
High Purity Grade
> 99.997% purity; filtered to ISO Class 1 particulate
level
Nitrogen
Cutting/Drilling
High Purity Grade
> 99.9500% purity; filtered to ISO Class 1 particulate
level
Oxygen
Cutting/Drilling
Ultra-pure Grade
> 99.9998% purity; filtered to ISO Class 1 particulate
level