Dear all,

I go about building a preconcentration system for methane in small air 
samples.
Did anyone use Valco switching valves (6port, 1/8 or 1/4'', type 6UWE or 
6MWE2) under vacuum conditions?
What leak rate did you observe at which pressures? Any recommendations 
concerning the switching between vacuum conditions in one postion and 
non-vacuum in the other?

Any infomation will be very much appreciated...

Regards
Michael

-- 
Michael Bock
Alfred Wegener Institute for Polar and Marine Research
Am Alten Hafen 26
27568 Bremerhaven
Germany
tel: +49-471-4831-1967
lab: +49-471-4831-1026 
fax: +49-471-4831-1926
email: [log in to unmask]