FID won't light

Chromatography Forum: GC Archives: FID won't light
Top of pagePrevious messageNext messageBottom of pageLink to this message  By Amy Egan on Wednesday, April 21, 2004 - 05:35 am:

I have a HP 5890. I have a FID that won't light, or if I get it to light it blows out. My column flow is 6 ml/min, make-up gas is 30 ml/min (I have tried lowering this.), air is 300 ml/min, and hydrogen is 30 ml/min. I have tried increasing the hydrogen flow (which works sometimes)and decreasing column flow. I have to light it with a lighter because my glow plug does not work. I have cleaned the detector multiple times and have a brand new jet. Does anyone have any ideas?


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Durk on Wednesday, April 21, 2004 - 06:43 am:

Amy,

Which gas you are using as carrier? What are the dimensions of your column?

Durk


Top of pagePrevious messageNext messageBottom of pageLink to this message  By DR on Wednesday, April 21, 2004 - 07:00 am:

Get a flow meter & check your carrier & air flows independently. Then just keep bumping the H2 'till it stays lit. Usually they blow themselves out when the H2 is too high. As a last resort, you may have to run the H2 a bit high to get it lit & then back off a bit to keep it going.

People make better things than bics to light FIDs. Get one of those too. They look like bbq lighters but they have a nichrome wire on the end and are full of batteries instead of butane.


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Amy Egan on Wednesday, April 21, 2004 - 07:14 am:

I use Helium as a carrier. I have a MXT-5 column (30m, 0.53mm, 0.50um).


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Anonymous on Wednesday, April 21, 2004 - 09:33 am:

I used to have a 5890 with the same problem. I turned off the make-up gas, and reduced the air flow but left the hydrogen at 30. After lighting the flame, increase the air, then the make-up gas slowly to operating conditions.


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Consumer Products Guy on Wednesday, April 21, 2004 - 09:51 am:

If your HP5890 glow plug doesn't work, take a 5/16 open end wrench, loosen it half-turn, then re-tighten. Then do the same for the screws that mount the FID. This is to restore electrical contact, we need to do this regularly; a bad glow plug is not expensive or difficult to replace (if it's a 5890A I'd just solder a new one on, the newer ones have a quick-connect). Also, make sure to clean the detector and jet at least once per year. Another trick is to gently blow into the FID while the ignitor is glowing, we do that sometimes, too.


Top of pagePrevious messageNext messageBottom of pageLink to this message  By DR on Thursday, April 22, 2004 - 09:38 am:

^^ I forget that trick - slight turbulence is frequently a good thing when lighting them. A gentle breath or fanning with the hand or a piece of paper...


Top of pagePrevious messageNext messageBottom of pageLink to this message  By ced on Thursday, April 22, 2004 - 12:03 pm:

When difficult to light,try as follow.
-turn make up gas off
-turn H2 off
Wait 30s
-turn Air on and gently open the Hydrogen until the flamme is lightning,and open full H2 and finally the make up.


Top of pagePrevious messageNext messageBottom of pageLink to this message  By jem98h on Friday, April 23, 2004 - 08:42 am:

I had the same thing happen a couple of months ago...apparently my problem was an old flame jet. I sonicated it, but that didn't help. Once I verified my glow plug worked and changed out the jet for a new one, I had no more problems.


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Amy Egan on Thursday, April 29, 2004 - 10:51 am:

Thanks for all of your help!! I got it to light!


Top of pagePrevious messageNext messageBottom of pageLink to this message  By ced on Friday, April 30, 2004 - 01:07 am:

Hi
HOw do you get it to light?

Thanks


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Amy on Tuesday, May 11, 2004 - 06:47 am:

I pushed the ignitor button (which doesn't ignite) while blowing (slightly into the detector) a flame across the top. I also set my carrier gas flow back a little, then brought it up to where it should be after the jet had been lit for a few hours.


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