HP 5890 Series II Plus Reference Manual page 166

Preventive Maintenance
Split/splitless capillary inlets
6. Turn off flow to the inlet by turning off carrier gas at the flow
controller (fully clockwise, turning it only until it bottoms, and then
no further).
7. Adjust the back pressure regulator clockwise, an additional 1/4•turn
or set the electronic pressure control to 145 kPa (21 psi) and observe
column pressure at the gauge for about ten minutes.
If the system is leak•free,pressure will remain between 131 and 138 kPa
(19 to 20 psi); if it drops, a leak exists. If there is leakage, turn on the
carrier gas supply and
Use a suitable leak•detectionfluid to check appropriate plumbing
connections behind the flow panel and onto the supply itself. Repair
or replace fittings and components as necessary.
Leak•detectionfluids often leave contaminating residues: After each
Caution
application, the area checked should be rinsed with CH
and allowed to dry.
Check the inlet itself at three possible locations:
-
-
-
Note: The following checks may be done at any time during normal
operation without either disconnecting the column or sealing the inlet.
Simply pressurize the system and check for overall leak•down.
Check for septum leakage by using a bubble flow meter: press its
inlet tube onto the top of the inlet needle guide (septum retainer nut).
Making sure the tube is flush with the surface of the inlet, check the
bubble meter for evidence of leakage. Replace the septum if leakage is
observed.
166
The septum.
The column connection.
The seal (O•ring)around the insert retainer nut.
OH (methanol)
3