To the vacuum practitioner, total pressure is the sum of the partial pressures
of the various gases making up the vacuum environment.
(1994) studied the influence of [H.sub.2]S partial pressure
on the activity of model Mo[S.sub.2]/A[L.sub.2][O.sub.3] over a wide range of [H.sub.2]S partial pressure
from 0-0.3 MPa, under a total pressure of 6 MPa, at 320-410[degrees]C and 0.5-0.7 [h.sup.-1].
Managing water vapor in a vacuum chamber by adding a supplemental water vapor cryopump and cryocoil can cut pumpdown time, increase product throughput, and lower water vapor partial pressure
during processing for high quality, better adhesion, and more reproducible deposition.
For example, in the lung bases where alveoli are better perfused than ventilated, the P[O.sub.2] tensions in the blood tend to be low and the PC[O.sub.2] partial pressures
are predisposed to be higher.
Process specifications are usually established in terms of a target total pressure or partial pressures
of specific problem gases before the process is initiated.
These are called contamination resulting in additional partial pressure
A Faraday cup detector is standard with both systems, allowing partial pressure
measurements from [10.sup.-5] to [10.sup.-8] torr.
Once base vacuum is reached and deposition commences, the high-speed pumping of water vapor must continue if residual water vapor partial pressure
is to be kept low in the face of its continual outgassing.
In either case, detector output is proportional to the partial pressure
of the particular gas species that traversed the mass filter.
Another of these "smart" RGAs is the Partial Pressure
Transducer (PPT), from the NGS Div.
They showed that background partial pressures
in an ultrahigh vacuum sputtering system can be reduced by an order of magnitude when the system is pumped with a cryogenic pump, rather than a slower turbomolecular pump.
The increase in temperature caused considerable changes in the partial pressures
of [O.sub.2] and C[O.sub.2] inside the packages during the storage period.