Agilent Technologies 7000 Series User Manual

6 Operating in CI Mode
High Vacuum Pressure in CI Mode
132 7000/7010 Series TQ GC/MS Operating Manual
High Vacuum Pressure in CI Mode
The largest influences on operating pressure in CI mode are the reagent and CC
gas flows. Table 10 lists typical pressures for various reagent gas flows,
depending upon the CC gas flowrate. 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 MS to the next.
Analyzer vacuum with reagent gas flowing
Note that the MFC is calibrated for methane and the vacuum gauge is calibrated
for nitrogen, so these measurements are not accurate, but are intended as a
guide to typical observed readings. (See Table 10.) They were taken with the
following set of conditions. Note that these are typical PCI temperatures:
Source temperature 300 °C
Front quad temperature 150 °C
Rear quad temperature 150 °C
Interface temperature 280 °C to 320 °C
Helium carrier gas flow 1 mL/min
Table 10 Typical analyzer vacuum with reagent gas flow
CC gas flow on
N
2
= 1.5, He = 2.25

CC gas flow off
MFC (%) Rough vac High vac Rough vac High vac
10 1.77
×10
–1
7.15 ×10
–5
1.33 ×10
–1
2.56 ×10
–6
15 1.86 ×10
–1
7.19 ×10
–5
1.43 ×10
–1
3.00 ×10
–6
20 1.94 ×10
–1
7.23 ×10
–5
1.53 ×10
–1
3.45 ×10
–6
25 2.02 ×10
–1
7.27 ×10
–5
1.63 ×10
–1
3.86 ×10
–6
30 2.10 ×1
–1
7.31 ×10
–5
1.71 ×1
–1
4.30 ×10
–6
35 2.18 ×10
–1
7.39 ×10
–5
1.80 ×10
–1
4.76 ×10
–6
40 2.25 ×10
–1
7.43 ×10
–5
1.88 ×10
–1
5.18 ×10
–6

Agilent Technologies 7000 Series Specifications

General

Brand	Agilent Technologies
Model	7000 Series
Category	Industrial Equipment
Language	English