The drive towards dry vacuum pumping has occurred across the spectrum of va
cuum applications from semiconductor manufacture to industrial processing.
This brings with it a need to systematically evaluate and quantify the degr
ee of cleanliness characteristic of any particular pump; currently, there i
s no universally accepted method to perform this function. A methodology de
veloped for repeatable measurements of pump cleanliness will be discussed.
It utilizes residual gas analysis with carefully controlled pump conditions
. This facilitates direct comparisons of the degree of cleanliness between
pumps of the same and those of different design. Additionally, it allows fo
r the assessment of methods (either in pump design or use) introduced to im
prove cleanliness. (C) 2000 American Vacuum Society. [S0734-2101(00)11303-1
].