Controlling Collision Cell Flow; Venting The Ms - Agilent Technologies 7200 Operation Manual

The MS can be used to measure actual column flow. You inject a small amount
of air or other unretained chemical and time how long it takes to reach the MS.
With this time measurement, you can calculate the column flow. See
Calibrate the Column"

Controlling Collision Cell Flow

The collision cell gas flow rate is controlled by an EPC module located in the
GC. The collision cell gas flow consists of nitrogen. The gas pressure at the
EPC outlet controls the flow of the gas. This pressure is controlled by the
MassHunter Data Acquisition Workstation or directly at the GC keypad. See
"To Set the Collision Cell Gas Flow Rate"

Venting the MS

A program in the data system automates the venting process. It turns off the
GC and MS heaters and the turbo pump at the correct time.
The Fast Vent feature loads a user-defined GC method that sets an oven
temperature, turns off the transfer line heater and sets the column flow to a
user predefined level.
The MS will be damaged by incorrect venting. A turbo pump will be damaged if
it is vented while spinning at more than 50% of its normal operating speed.
The use of hydrogen gas is specifically prohibited with this product.
WA R N I N G
Never vent the MS by allowing air in through either end of the foreline hose. Use the
C A U T I O N
vent valve or remove the column nut and column.
Do not exceed the maximum recommended total gas flow. See
7200 Accurate-Mass QTOF Operation Manual
Operating in Electron Impact (EI) Mode
on page 46.
on page 49.
"To
Table 2.
39
3