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H2 generator - min. flow rate for HP5890/FID.
Posted: Mon Feb 27, 2017 9:21 pm
by lespaul
We're setting up a new lab and we're considering purchasing a H2 generator.
Does anyone know the minimum flow rate required to run a HP5890 w/FID? I've seen they can range from 300mL/min to 2,000ml/L.
From what I've seen here the Ebay generators (China) seem to work quite well...although I would prefer a used Parker Balston if I can find one within budget.
As far as use, we're small startup lab so their will be minimal sample throughput.
Re: H2 generator - min. flow rate for HP5890/FID.
Posted: Mon Feb 27, 2017 10:13 pm
by Consumer Products Guy
Our first hydrogen generator was/is a Parker Balston model capable of 500ml/min. We used that to feed the FIDs of at least four 5890 and 6890 units, as each FID used 40ml/min or less. When we decided to go to hydrogen carrier gas in at least one of the GC units, boss wanted more hydrogen capacity, even though I tried to convince him that these were not all used at once. So we got two Balston Parker units of 850ml/min each, so now have all three plumbed up.
So if you have just one GC, 500ml/min would be PLENTY for both carrier gas (if you wanted) and FID.
Re: H2 generator - min. flow rate for HP5890/FID.
Posted: Tue Feb 28, 2017 7:40 am
by tkubowicz
Hello
So if you have just one GC, 500ml/min would be PLENTY for both carrier gas (if you wanted) and FID.
One thing to keep in mind is split ratio. If it is really high (50-100) it can be problem to keep H2 flow stable. Of course gas saver can do the trick but I've seen GC with generator (500cc) and from time to time there was problem with some methods.
Regards
Tomasz Kubowicz
Re: H2 generator - min. flow rate for HP5890/FID.
Posted: Tue Feb 28, 2017 7:58 am
by Peter Apps
Bear in mid that as flow goes up, purity goes down so you need to look at what flow it can deliver at the purity level you need, not what it can crank out when running full blast.
Peter
Re: H2 generator - min. flow rate for HP5890/FID.
Posted: Sat Mar 04, 2017 10:05 pm
by lespaul
Thanks everyone for your help.
I may pickup a Perkin Elmer H2 from a local supply shop - anyone have any experience with these models? I would prefer a Parker Balston
Re: H2 generator - min. flow rate for HP5890/FID.
Posted: Thu Mar 16, 2017 6:56 pm
by Jake
To add to Peter's comment, you don't want to run your H2 at greater than 85-90% for a prolong length of time. So for a method at 1 mL/min column, at 400:1 split, with the generator supplying FID fuel too, you're at capacity. We've run under those conditions in the past, so they're not unheard of. If you're no where near that, you'll be fine. We ran a 3.4 mL/min column, 40:1 split, 40 mL fuel for years on a 500 mL/min generator.