HP 5890 attenuation issue

[fla4ritup]

Old faithful 5890 - this am showed 8333000 as baseline attenuation that can't be changed- happened a year or so ago, was corrected but no one in the lab can remember what corrected it. Anyone ever seen this before?

[cleh]

Are you using Chemstation or an integrator? Does the signal go down if you shut off the flame? Did you do any maintenance or repairs before this happened? The spring from the electrometer PCB to the collector could be shorting or have moisture on it causing it to short. If it's not shorting, could be a bad electrometer.

[rb6banjo]

This might be painfully obvious but I've seen this sort of thing fix stuff in the past. Did you try shutting the system down and bringing it back up?

[kubowicz.tomasz]

Hello

Similar value (around 800000) is when there is short circuit in FID.
I'd recommend check FID:
-jet (scratches etc.)
-insulation disks
-spring (perhaps is bent or not aligned properly)

Regards

Tomasz Kubowicz

[skunked_once]

-spring (perhaps is bent or not aligned properly)

This has happened to me. The spring can get bent and contact the collector.

[fla4ritup]

Are you using Chemstation or an integrator? Does the signal go down if you shut off the flame? Did you do any maintenance or repairs before this happened? The spring from the electrometer PCB to the collector could be shorting or have moisture on it causing it to short. If it's not shorting, could be a bad electrometer.

Thanks, using Chem Station, I believe the "short" must be the case. Will check this out. Thanks

[fla4ritup]

This might be painfully obvious but I've seen this sort of thing fix stuff in the past. Did you try shutting the system down and bringing it back up?

Yes, tried that first- I am checking the collector for a short. Thanks

[fla4ritup]

Hello

Similar value (around 800000) is when there is short circuit in FID.
I'd recommend check FID:
-jet (scratches etc.)
-insulation disks
-spring (perhaps is bent or not aligned properly)

Regards

Tomasz Kubowicz

Thanks, Will check this out.

[fla4ritup]

-spring (perhaps is bent or not aligned properly)

This has happened to me. The spring can get bent and contact the collector.

Thanks, I'll check this out

[fla4ritup]

test

[fla4ritup]

It was the spring- not properly seated from the last overhaul of the FID- there was enough contact to make it work for several months but I could see where the spring was not situated in the "groove" on the collector. Took apart, cleaned,dried and reassembled- doing fine now- however getting the spring properly seated is tough. As you can tell, I'm new to this forum- think I understand the protocols of replying now-Thanks all.

[rb6banjo]

I have a very thin screwdriver that I used to hold that spring off to the side while I slip that collector in there. Then I pull out the screwdriver and the spring snaps into the groove. I'm glad you fixed your problem!

[fla4ritup]

Great idea! Thanks

[cleh]

I have a very thin screwdriver that I used to hold that spring off to the side while I slip that collector in there. Then I pull out the screwdriver and the spring snaps into the groove. I'm glad you fixed your problem!

Do the same thing! Glad your back in business!