Chromatography Forum

Hi all,
I am using agilent 6890A GC with FID. My FID flame is not turning on.I checked flow its ok. I am using Hydrogen and oxygen cylinders for FID.

Four questions

- how did you measure the flows ?

- how do you know that the flame is not burning ?

- are you using makeup gas ?

- what is your carrier gas, and at what flow rate in ml/min ?

Please confirm that you are feeding the FID with air and not oxygen.

Peter

Peter beat me to the punch as I was writing this. Very nice.

Hi,
I shut down GC and restarted method again. I dont know HOW amazingly everything is ok now. flame is on

Second rule of troubleshooting:

A problem that only happened once is not a problem

Peter

Sometimes we need to go to the pushbuttons on front of the 6890 GC and push the Ignition on and/or turn on all the gases if they go out and shut down. Not a big deal.

It's a whole lot different than blowing into the 5890 collectors !!!

No i did pressed on button too many times... actually i blew at collector also....

I sometimes have this kind of problem: have to wait about 30 min or more before the flame is on. When you shutdown and turn everything on, it have more time !.
You may have to clean/replace the jet.

I sometimes have this problem on a packed column with a high column flow(30-100mL/min). I have to reduce the flow to around 5mL/min and then ignite the flame. After a few minutes I turn the column flow back to it's desired setting and it stays lit.

Thank you all for replying,
Problem was with the jet. I cleaned it once its working properly
and sorry for not posting after its started working :p

Hello
Is still a few problems, except for blowing the flame a large flow of carrier gas.

(This is solved by the Related nozzle and correct selection costs of hydrogen and air. It is better to use a rich mixture. Carrier gas is better to switch gradually, 10,15,25,30 ml / min)

If you turn off the hydrogen at night, then hydrogen can flow from the detector tubing line to the atmosphere.
Then when you turn there are problems with the ignition, as the first line of the hydrogen comes less hydrogen. A few minutes later when re-ignition of the detector is working properly.

If you cleared the detector, it could damage the ignition coil, drown it in the slot.

Sometimes distinguishing the flames with water vapor (when introduced into the column 10mkl water samples), but it's not your case

Besides, I came across a sticking hydrogen solenoid valves .
This is solved by replacing the respective valve. At 6890 block of knockdown and this is its advantage over 7890. It's not your case


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