HP 5973 MSD, Hardware Manual

Page: 18 / 122

18
Hardware Reference
5HDJHQWJDVIORZFRQWUROPRGXOH
Reagent gas flow control module schematic
When you turn off one gas and turn on the other, the system sets a 6-minute delay
with
Gas Off
and
Purge
both on to pump out the flow control module. The light for the
selected reagent gas will flash, indicating the delay timer is active. Once the delay
is finished, the
Purge and Gas Off lights will turn off, and the light for the selected gas
will stop flashing and stay on.
When the MSD is turned off, all valves are closed, and all lights are off. At startup,
all valves are closed and all lights are off, except
Gas Off
.
The flow control board remembers the flow setting for each gas. When either gas is
selected, the control board automatically sets the same flow that was used for that
CI ion
source
Gas A
(Methane)
supply
Gas B
(Other gas)
supply
Mass
Flow
Controller
Gas select
valve A
Gas select
valve B
Restrictor
PFDTD
vial
Calibration
valve
Isolation
valve
EI/CI
GC/MSD
interface
Green
light
Amber
light
GC column