MKS Instruments UK Ltd
V2000-P Hardware Manual
– SP102006.103 March 2013
18
Leak checking
At this point you will have assembled the system, checked that it is working and you that you can see a
background spectrum. The next thing to do is to leak check the Vision 2000-P.
The vacuum system used in the Vision 2000-P was fully leak checked as part of the assembly and test
procedure before it left the factory. You need to leak check in case any leaks have occurred due to shipping
damage and to check the one seal you have made between the Vision 2000-P and the process chamber.
Ensure that the process valve is closed.
To leak check you will need a cylinder of helium fitted with a regulator and a length of flexible hose to spray
helium around the Vision 2000-P. You can use a different tracer gas (other than oxygen and nitrogen) as long as
it is safe and you modify the mass being monitored in the leak-hunting recipe accordingly. Helium is preferred,
and any grade will do.
Run a Leak Hunt recipe in Process Eye and check that the probe gas is set to mass 4 for helium (or the
appropriate mass, if you are using another gas).
As the Vision 2000-P uses a Microvision2 there can be an audio tone available via headphones or powered
speaker if enabled in the recipe. Alternatively, position the monitor so that you can see the screen while you are
leak-checking. Please consult the Microvision2 manual for details of the audio output.
Starting at the top of the Vision 2000-P vacuum system slowly and carefully spray helium over the entire system
paying particular attention to the vacuum seals. Watch the monitor or listen to the audio tone for a signal
indicating a leak.
Once the RGA vacuum chamber is leak-tight, check the part of the Vision 2000-P between the process valve
and the process chamber.
Open the process valve and spray helium over the valve, the seal to the process chamber and the connecting
pipe work.
If you do find a leak shut down the system, fix the leak and start again.
Remember you may need to break the seal between the Vision 2000-P and the process chamber in which case
you will also have to shut down the process chamber.
