Cannot Maintain A Pressure As Low As The Setpoint On A Split Inlet - Agilent Technologies 7890 Series Troubleshooting Manual

Cannot Maintain a Pressure as Low as the Setpoint on a Split Inlet

Table 5 Approximate minimum viable inlet pressures for inlet in split mode, in psi (split/splitless, multimode)
Helium and hydrogen carrier gases
Split liners - 5183-4647, 19251-60540
Splitless liners - 5062-3587, 5181-8818
Nitrogen carrier gas
Split liners - 19251-60540, 5183-4647
Splitless liners - 5062-3587, 5181-8818
Agilent 7890 Series Troubleshooting
If the GC cannot maintain a pressure as low as the setpoint,
check for the following:
• Consider using a liner designed for split analysis.
• Method pressure parameter (or resultant pressure from a
flow setting) is too low for the carrier gas type. See
Split/Splitless inlet split mode minimum operating pressures
or Multimode inlet split mode minimum operating pressures
and the table below.
Split vent flow (mL/min)
50–100
2.5
4.0
3.0
4.0
• Check for a plugged liner.
• Check for contamination or restriction in the split vent line.
See:
• To Perform a SS Split Vent Restriction
• To Check or Monitor Split Vent Line Backpressure
• To Run the Inlet Trap Check
• To Check a Split Vent Line for Contamination
• For the split/splitless inlet, replace gold seal..See
the Gold Seal on the Split/Splitless
GC Not Ready Symptoms
100–200 200–400
3.5 4.5
5.5 8.0
4.0 —
6.0 —
Test.
Inlet.
4
400–600
6.0
11.0
—
—
To Replace
99