Checking for Leaks 7
Agilent 7890 Series Troubleshooting 157
1
Gather the following (see Consumables and parts for the
COC inlet):
• No-hole ferrule
• 1/4-inch wrench
• Heat-resistant gloves (if the inlet is hot)
• Column nut
• New septum
• ECD/TCD Detector plug (part no. 5060-9055)
2 Load the inlet maintenance method and wait for the GC to
become ready.
3 Remove the column, if installed.
4 Plug the column fitting with a column nut and no-hole
ferrule.
5 Remove the old septum and replace it with a new one. See To
change a septum on the COC inlet.
6 Enter a pressure setpoint of 25 psi (172 kPa). Make sure that
the pressure supplied to the GC is at least 10 psi (70 kPa)
higher than the inlet pressure.
7 Wait 5 minutes for the pressure to equilibrate. If pressure
cannot be achieved, there is either a large leak or the supply
pressure is too low.
8 Set the Septum purge flow to 3.0 mL/min.
9 Allow the inlet temperature to stabilize. Temperature
changes can invalidate the test.
The test can find leaks at the: The test cannot find leaks at the:
septum column fitting
septum nut or cooling tower gas supply bulkhead fittings to the
flow module
seals within the tubing between the
inlet flow module and the inlet body
inlet body
To Next Page
Loading...
Need help?
General
