For those who do not often change things on a UHV
vacuum system, here's some tips if you need to mount a
viewport. First, never use a viewport that appears to
be, or is known to be damaged. A replacement viewport
costs far less than repairing a system that has been
subject of an implosion caused by a faulty viewport.
Kodial VPZ viewports are designed to withstand 1 Bar
differential pressure. Other standard viewports are
designed to withstand 2 Bar differential pressure. The
pressure on the ‘vacuum side’ of the viewport must not
exceed a positive pressure differential of 1 bar. The
viewports are designed for vacuum applications.
WARNING: Pressures in excess of this or high
reverse pressures may cause catastrophic failure and
result in serious injury.
Viewport bolt-up procedure: Always use annealed
copper gaskets and a washer with each bolt. Tighten
opposing mounting bolts equally over several passes. Use
a torque wrench to ensure equal sealing torque. Do not
over tighten. Failure to follow this procedure will
invalidate any warranty.
WARNING: The optic surface is very delicate and
will scratch easily. Always wear lint-free or surgical
rubber gloves when handling. Never touch the optic
Storage: It is recommended best practice that all
viewports are covered when not in use.
Use: If the viewport is to be used in a vacuum
system where materials are deposited or plasma cleaned,
an internal viewport shutter should be fitted.
Humidity: Anti-reflective coatings are durable and
resistant to atmospheric moisture and other common
WARNING: All viewports are supplied UHV clean and
ready for use. Optical coatings are typically 10-300nm
thick and as such are extremely delicate. Any materials
deposited or removed from the coating will affect
optical performance. Cleaning should only be attempted
when absolutely essential.
Dust: Dust should be removed using a particulate
and water-free low pressure air-gun, aerosol or puffer.
Light smudges (e.g. finger prints): Smudges should
be removed by wiping very gently using a lint free
optical quality wipe moistened with isopropanol (IPA).
Do not use tissue paper.
Other marks: Products with more serious marks and
contamination should be returned to the supplier for
cleaning and/or recoating.
Baking: When baking, ensure the viewports are
shielded from direct heat and strong temperature
gradients, by, for example covering them with aluminium
Heating / Cooling rates: Heating and cooling rates
must be kept below 3°C/min.
Exceeding the temperatures bellow can invalidate
||Max Temp C