To Perform A Mmi Pressure Decay Test; To Perform A Multimode Inlet Pressure Decay Test - Agilent Technologies 7890 Series Troubleshooting Manual

7
Checking for Leaks

To Perform a MMI Pressure Decay Test

To Perform a Multimode Inlet Pressure Decay Test

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Use the Agilent Instrument Utilities Multimode Inlet Pressure
Decay Test to determine if the inlet is leaking. Open the
software, select the GC, and run the test for the inlet.
If the Instrument Utilities software is not available, see the
procedure below.
If the test fails:
• Check the plugged column fitting and septum purge cap.
• Check the septum head. Tighten if needed.
• Replace the septum if necessary.
• Inspect and re-install the liner if it is leaking.
• Tighten the split vent trap if needed, or install a new
cartridge and O-rings.
• Tighten the split vent line connection to the inlet.
The pressure decay test checks for leaks from the inlet flow
module up to the column fitting.
After performing maintenance, first check for leaks in
externally accessible areas. See
If a leak is known to exist, check the externally accessible inlet
fittings first, especially any connection that has seen recent
maintenance, such as the septum nut, column adapter, column
connection, and so forth.
The pressure decay leak test described below requires removing
the column and capping the inlet column fitting. This test
can/cannot find the following types of leaks:
To Check for External
Agilent 7890 Series Troubleshooting
Leaks.