Faults which may occur
after a certain period
Peak areas become smaller, calibration factors larger
Cause Remedy
Live switching is maladjusted Readjust the live switching
The solenoid valve MV
Cut
does not close properly in
one or the other position
(aging). The differential
pressure is then too low
Replace solenoid valve
MV
Cut
Peaks appear at positions where they do not interfere
Cause Remedy
Live switching is maladjusted Readjust the live switching
The solenoid valve MV
Cut
does not close properly in
one or the other position
(aging). The differential
pressure is then too low
Replace solenoid valve
MV
Cut
Peaks superimposed on one another
Cause Remedy
Live switching is maladjusted Readjust the live switching
The solenoid valve MV
Cut
does not close correctly in
one or the other position
(aging). The differential
pressure is then too low
Replace solenoid valve
MV
Cut
The cut time is suddenly poor
Cause Remedy
Aged columns, blockages or
leaks are present
Readjust the live switching,
replace columns if
necessary
Maintenance of live switching
The live T-piece is maintenance-free. However, packing
material may block the coupling capillary or the annu-
lar clearance between the coupling capillary and the
column. The live T-piece must then be replaced.
Always recommendable: compare with calibration ana-
lysis from time to time!
Live switching: troubleshooting
live.chp, Issue August 17, 1999
6 - 11