Hi Mike-
Sounds like you're sucking air...
You may have to replumb it, but make sure you're getting He flow to the open
splits--check both the He make up gas and the flow in from the GC.
Occasionally we've had our capillaries catch and do a curly Q and suck
air
instead of going straight down. It's also possible you have have a crack in or
inside of a ferrule.
good luck...
take care
gerry
Quoting "Kubo, Michael D. (ARC-SSX)[SETI INSTITUTE]"
<[log in to unmask]>:
> Hi Isogeochemers,
>
> After troubleshooting for a bit, I think my original diagnosis was
> incorrect. It turns out that the pump HV source light kicks back on
> when I closed the GCC valve, but didn't go out when I opened the
> Conflo valve - just normal vacuum. I tried switching the capillaries
> between the different valves and when they were switched, the results
> were switched - improper vacuum on what was the Conflo valve (but now
> had GCC capillaries going into it) and normal (2.2 x10^-7) on what
> was the GCCIII valve (now with the conflo capillaries going into it).
>
> So there is clearly something wrong - probably a leak - with my
> system upstream of the capillary/SGE valve interface. I tried
> clipping about 3 cm of capillaries off of the inlet, in the hopes
> that I had some kind of small crack right by the inlet nut on the
> capillaries, but that didn't do anything. At this point, I'm not
> quite sure how to approach this. My gut reaction would be to tear
> out the capillary coming from the GCCIII interface and replumb it
> into the source, but this seems a bit extreme.
>
> Any thoughts?
>
> Thanks again,
> Mike Kubo
>
>
>
> ________________________________
> From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On
> Behalf Of Kubo, Michael D. (ARC-SSX)[SETI INSTITUTE]
> Sent: Wednesday, July 29, 2009 1:23 PM
> To: [log in to unmask]
> Subject: [ISOGEOCHEM] Source HV Down on a ThermoFinnigan Delta Plus XL
>
> Hello Everyone,
>
> Of course, just before I'm about to run a 1 shot meteorite sample,
> our HV just went down. Here is the play by play:
>
> 1) Had been running EA, so before I opened the GC-C-III SGE
> valve, I turned off the filament HV button the front panel so as not
> to flood the source with gas and trip the HV.
> 2) Came back around to the front side of the instrument panel
> to turn the source HV back on. Depressed button, only to see that
> neither the source HV light or the emission light came on, but the
> red LED on the button did. In addition, the source HV light on the
> pump LED panel was also off. Source vacuum indicates 3.3 X 10^-5 -
> clearly not the vacuum of 10^-6/10^-7 I typically operate at.
> 3) If I try power cycling the "pump" switch on the front of the
> instrument, the pump source HV LED will flash twice, then stay out.
>
> So my guess is that I have a bad source turbo and the source HV won't
> kick on because of this. If anyone out there has other ideas that
> don't involve weeks of downtime and several (tens of) thousands of
> dollars to repair, PLEASE shoot me an email! Your help is greatly
> appreciated (as always) and a lonely chunk of meteorite will be very
> grateful as well.
>
> Cheers,
> Mike Kubo
>
>
>
> ****************************************************************************************************************************************
> Michael D. Kubo
> NASA Ames Research Center
> M/S 239-4
> Bldg. N239, Room 327
> Moffett Field, CA 94035
>
> (650) 604-6110
>
>
|