Agilent Technologies 5975 Operation Manual page 112

4
Operating in Chemical Ionization (CI) Mode
The shutoff valve prevents contamination of the flow control module by
atmosphere while the MSD is vented or by PFTBA during EI operation. The
MSD monitors will reflect On as 1 and Off as 0 (see
Gas A
(methane)
supply
Gas B
(other)
supply
Figure 21 Reagent gas flow control module schematic
Table 17 Flow control module state diagram
Result Gas A flow
Gas A Open
Gas B Closed

MFC On setpoint
112
Gas A
select valve
Gas B
select valve
Gas B flow Purge
with Gas A
Closed Open
Open Closed

On setpoint On
Mass
flow
controller
Calibration
valve
Restrictor
Calibration
vial
Purge
with Gas B
Closed
Open
 
100% On 100%
5975 Series MSD Operation Manual for MassHunter
Table 17).
CI ion
source
Shutoff
valve
GC/MSD
interface
GC column
Pump out Standby,
flow module vented, or EI
mode
Closed Closed
Closed Closed
 
On 100% Off 0%