Agilent Technologies 5977C Series - Page 138

5 Operating in CI Mode
To Monitor CI Mode High Vacuum Pressure
138 5977C GC/MSD Operating Manual
Familiarize yourself with the measurements on your system under operating
conditions and watch for changes that may indicate a vacuum or gas flow
problem. Measurements will vary by as much as 30% from one MSD and gauge
controller to the next.
Table 15 MFC settings and typical pressure readings
MFC Pressure (Torr)
(%) Methane Ammonia
EI/PCI/NCI MSD
(Turbo pump)
EI/PCI/NCI MSD
(Turbo pump)
10 5.5
×10
–5
5.0 ×10
–5
15 8.0 ×10
–5
7.0 ×10
–5
20 1.0 ×10
–4
8.5 ×10
–5
25 1.2 ×10
–4
1.0 ×10
–4
30 1.5 ×1
–4
1.2 ×10
–4
35 2.0 ×10
–4
1.5 ×10
–4
40 2.5 ×10
–4
2.0 ×10
–4