5
Troubleshooting
70
User Guide
Checking for Leaks
After installing a column module, if the GC inlet cannot maintain pressure, first check the
connections between the column module and the CFT unions.
Otherwise, use an electronic leak detector to check each of the union and other connections.
Perform a normal inlet leak checks and pressure decay tests as described in the GC
documentation.
Perform detector leak tests as described in the GC documentation.
You can perform a pressure decay test by plugging the end of the column segment leading to
the detector, or by using a CFT plug fitting (made from a piece of wire and normal UltiMetal
ferrule) in the detector side of the CFT union. However, compared to a non-LTM system, the
additional volume provided by the column segments will cause some initial, extra pressure
decay until the setpoint pressure equilibrates throughout the system. After the initial decay,
however, the inlet pressure should stabilize to a normal decay rate. (Because of the additional
internal volume, the
amount
of decay may be larger than listed in the GC documentation but
still be acceptable.)
