Checking for Leaks 7
Agilent 7890 Series Troubleshooting 169
changing the source pressure is not practical, skip this step.
If there is a relatively large volume in the supply tubing
leading up to the GC, consider whether or not there could
have been a leak into the system when evaluating the test
results.
18 Monitor the pressure for 10–15 minutes. Use the timer by
pressing [Time] and [Enter].
The pressure should drop approximately 1 psi (6.9 kPa)
during the first 1 to 2 minutes. After an initial pressure drop
of about 1 psi, the pressure should not drop more than
0.03 psi/min (0.21 kPa/min).
If the pressure drop is 0.03 psi/min or less, you can consider
the interface-gas sampler system leak-free.
If the pressure drops faster than the acceptable rate, you
must check the interface and sampler systems separately to
determine the source of the leak. See “To Prepare the VI for a
Closed System Leak Check” to create a closed flow system,
then return to this section and complete steps 10 to 16.
If you find a leak in the interface, refer to “To Correct Leaks
in the Volatiles Interface”.
If the interface is leak-free, pressure check the sampling
device. See the operating manual for your sampler for
instructions.
19 After the VI passes the test, restore the GC to operating
condition.
• Restore source pressures.
• Remove any caps/plugs.
• If needed, reconnect the sampling device.
• Reinstall the column.
• Restore the correct column configuration.
• Load the operating method.
To Next Page
Loading...
Need help?
General
