Chromatography Forum

I have an FID on an HP 5890 II GC. The ignitor went out while ago, and it needs to be lit with an external ignitor (i.e. a grill lighter). However, recently it has not been lighting (or staying lit once it ignites). I have cleaned the FID jet. Can anyone offer any troubleshooting advice?

I'm a newbie, so take it easy on me if there's something simple that I overlooked. Thanks.

Dear Organicdude, I suggest you to have a look on maintenance book of your GC, check the sparepart number of the ignitor and change it.

Best reagrds

Davide

organicdude,

You might want to make sure that the flow rates of the flame gases are still set correctly. I am not familiar with the 5890II GC butyou probably need to use a flow meter and plug up the column connection to the detector. Make sure to include the make-up gas flow if you use it also in your flow checks.

Regards,
Mark

Check your gas flow!

As the other responders noted, check the FID gas flows. We normally use 30 ml H2, 300 ml air, and 30 ml make up gas if using capillary. let the gases flow 10 minutes. Now, first question is: does the ignitor glow when you hold the ignitor button down? If not, unscrew it a turn (5/16 wrench), then re-tighten it. Also get out your #2 Posidrive screwdriver and loosen, then re-tighten the FID screws. This is to make sure you have a good ground circuit. The ignitor itself can be checked out with a multimeter, it should read a few ohms, not be "open". If this all checks out, while you're holding the ignitor button in and getting that nice orange glow, blow gently into the FID. It sounds dumb, but we do that frequently, and it works.

Thanks, everyone. I will follow up your suggestions with actions!

od

The 5890II has the plastic gas shut offs with the push button restrictors. I've had times when the restrictors could be pushed in but never returned to the out position. The Fid would light but blow out when hit with hydrocarbon or a little breeze. Now people have said that all you need to do is lubricate the valves, but I've never had luck with that. I ended up replacing the entire manifold.
I've never replaced my ignitors after they break. I too use the grill lighter with no problems. The ignitor wires get brittle and break off from the heat.

I too use the grill lighter with no problems.

haha, I always thought I was the only one who did this...

od