Gas
Control System
PlasmaQuant MS Series
36
The selected plasma flow passes through a combination passage and the reservoir
assembly to the torch. The plasma orifice jewels are sized to deliver 1.5 L/min, 3.0
L/min, 6.0 L/min, and 12 L/min for a maximum flow of 22.5 L/min. The reservoir
assembly aids reliable plasma ignition and helps dampen gas flow changes to the
torch.
During an ignition sequence, the plasma gas carries the spark discharge from the
igniter assembly to the torch. The igniter is located under the RF enclosure.
The selected auxiliary flow passes through a combination passage to the torch. The
auxiliary gas flow orifice jewels are sized to produce 0.15 L/min, 0.3 L/min, 0.6 L/min
and 1.2 L/min for a maximum flow of 2.25 L/min.
Solenoid
Function
SV10
Controls supply of argon to the gas box system
Gas_Enable
SV1 - SV4
Controls the plasma gas flow to the torch
0 - 22.5 L/min
SV6 – SV9
Controls the auxiliary gas flow to the torch
0 – 2.25 L/min
IV1 (SV11)
Controls the small isolation valve solenoid
Open_Closed
GV1
Controls the supply of argon to the gate-valve solenoid
Open_Closed
Table 3 - Solenoid valve functions within gas control assembly
The mass flow controller (MFC) supplies a specified flow of argon gas. The mass flow
controllers are connected directly to the system control PCB. An analog voltage from
the system control PCB sets its flow rate. The maximum argon gas flow is set at 1.5
L/min. The mass flow controller also provides an output voltage proportional to the
actual flow achieved.
NOTE
This assembly cannot be serviced and must be replaced at module level.
The second Norgren regulator (RG2) within the gas box assembly is used to supply
argon gas to the mass flow controller 1 (MFC1), which supplies the nebulizer.
The gate valve and large isolation valve solenoids get pressure directly from the argon
supply.
The nebulizer gas mass flow controller (MFC1) controls the nebulizer gas flow. It is
identical to the mass flow controller used to control the sheath gas and therefore can
be interchanged for troubleshooting purposes.
The gate and large isolation valve solenoids open and close the gate and large
isolation valves respectively. They are gas-actuated assemblies used to isolate the high
vacuum system from the atmosphere. Applying gas to a two-position, piston-driven
solenoid drives each valve. Driving the piston one way closes the valve, while driving it
the other way opens it.
Solenoid valve functions