Low Sensitivity Or Poor Repeatability - Agilent Technologies 7890 Series Troubleshooting Manual

Low Sensitivity or Poor Repeatability

Agilent 7890 Series Troubleshooting
• Split vent line connection to the inlet body
• Flow block fittings on the flow manifold
Alternately, use an electronic leak detector to check these
fittings/connections.
If these checks do not resolve the problem, contact Agilent
for service.
A small leak in the split/splitless EPC inlet can cause low
sensitivity or poor repeatability. Check for and isolate a small
leak as described below.
If you have recently performed maintenance, first check for
leaks on any fittings/parts you handled.
1
Perform the inlet pressure decay test. See
Pressure Decay Leak
inlet leak-free and check other possible causes for the low
sensitivity or poor repeatability.
2
If the pressure decay test fails, perform the inlet leak check.
See "To Perform an Inlet Leak
while checking/tightening fittings:
• Septum nut
• Column
• Split vent trap
• Liner/O-ring
• Gold seal
• Split vent line connection to the inlet body
• Flow block fittings on the flow manifold
3
If the inlet (prep run) leak check did not resolve the problem,
the leak may be too small to detect using that test. Use an
electronic leak detector to check the fittings/connections.
If these checks do not resolve the problem, contact Agilent for
service.
Checking for Leaks
"To Perform a SS
Test". If the test passes, consider the
Check". Monitor the total flow
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