1.4. Vacuum Operation
There are two vacuum preparation options:
l
Low Vacuum (for use in atmospheric pressures to 10
-3
Torr)
l
High Vacuum (preparation for environments from 10
-3
to 10
-6
Torr).
Special preparations include:
l
Parts are lubricated with vacuum-compatible lubricants.
l
Materials, fasteners, and coatings with vacuum outgas performance are ensured to be compatible
with the specified level of vacuum.
l
For high vacuum systems, situations that may allow gases to become temporarily trapped during
pump down are removed.
l
Prior to assembly, stage parts are thoroughly cleaned in a clean environment.
l
The stage is packaged in a special polyethylene bag.
Vacuum Guidelines
To ensure that the stage will continue to perform well in the vacuum environment, follow the guidelines
listed below (in addition to standard handling, installation, and lubrication guidelines outlined in this
manual).
1. Do not remove the stage from its sealed bag until it is ready for use.
2. Always handle the stage in a clean environment and use powder-free polyethylene gloves to prevent
any contaminants from adhering to the surface of the stage.
3. During installation, use cleaned, vented, stainless steel fasteners to secure the stage.
4. Reduced air pressure eliminates significant convective heat transfer. This, coupled with the viscous
vacuum-compatible lubricants, could result in excessive motor operating temperatures. Because of
this, consider all continuous torque ratings to be 40 to 60% lower than the value specified for oper-
ation in normal atmospheric environment. Reduce motor usage accordingly.
5. We recommend that you use a small quantity of
Braycote® 602EF
grease or a compatible substitute
of equal quality lubricant in vacuum applications.
6. Bake vacuum components at 60 °C for 24 to 48 hours to significantly reduce outgassing at initial
pump-down to vacuum pressure and evaporate water vapor that impregnates porous surfaces on the
aluminum and Teflon cables. Aerotech recommends that customers bake out vacuum systems when
first installing them in the vacuum chamber. Contact Aerotech to discuss your application and the
recommended bakeout procedure.
1.4. Vacuum Operation
ECO225SL Hardware Manual
18
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