Enabling the Electronic/Automatic Septum purge flow on COC

[Minas Iakovides]

Dear friends,
newbie in this forum, sorry if this is a topic already discussed.

I am trying to figure out how could someone enables the electronic septum purge flow on an Agilent 7890B GC equipped with an COC inlet.

I am facing air leaks and the low septum purge flow is the cause.

When in inlet menu, the septum purge flow is checked.

Could someone please tell me how can I enable it?

thanking you in advance,
kind regards,
Minas

[Rndirk]

At what flow is the septum purge now? It's common to use 3-5 ml/min. I don't see how it can cause leaks though.

[Minas Iakovides]

Dear friend,
thanks for your response,

the flow is set to 10mL min-1 and air leak still occurs.
Nevertheless, supposed to be automatically controlled, so as to preventing air leak.

Don't know what to say.

Many thanks,

[Minas Iakovides]

Forgot to say that the septum purge flow should be around 3-10mL min-1, according to the manual.

Many thanks again,
cheers,

[Rndirk]

How do you detect the leak and why do you think it's because of the septum purge flow?

[Peter Apps]

Dear friend,
thanks for your response,

the flow is set to 10mL min-1 and air leak still occurs.
Nevertheless, supposed to be automatically controlled, so as to preventing air leak.

Don't know what to say.

Many thanks,

The function of a septum purge is to carry contaminants that diffuse out of the septum away from the column - it is not there to prevent air leaks. If you have a leaky septum the air will still get onto the column at any sensible setting for the septum purge flow rate, the way to fix this is to replace the septum. You can verify your septum purge flow using a flow meter at the septum purge outlet.

Peter