HI Stewart--

Thanks for sharing.  We've been doing jump calibrations more than usual 
on our DeltaV--I never would have guessed that kind of magnet problem.

take care,


On 1/26/2017 6:16 AM, Bishop Stewart Eric wrote:
> Good Day Rich,
> I trust you have a EA/Delta V Plus set up. If not read no further but 
> might be useful for others. We had very similar issues in 2015 with 
> our dual measurements CO2 ref values thinking it was due to jump 
> calibrations or magnet calibrations errors or…. We ended up doing 
> individual N and C only measurements.
> The solution was to have the Delta’s electro magnet removed, cleaned 
> and plates inserted to shield it from the Aluminum housing. Apparently 
> it accumulates sticky static particles. This definitely did the trick 
> after long troubleshooting days.
> Hope this helps
> Stewart
> *From:*Stable Isotope Geochemistry [mailto:[log in to unmask]] 
> *On Behalf Of *Dabundo, Richard C
> *Sent:* Wednesday, January 25, 2017 5:41 PM
> *To:* [log in to unmask]
> *Subject:* [ISOGEOCHEM] Elemental Analyzer CO2 reference peaks
> Hello,
> I'm having an issue with CO2 reference peak deviation during an 
> Elemental Analyzer N and C run. Two CO2 reference peaks are produced 
> following the C sample peak. Originally, the first peak was 
> consistently ~1.1‰ lighter than the second peak. After creating a new 
> N2 to CO2 jump calibration, the first reference peak 
> became consistently heavier than the second by about 0.6‰. We 
> have sufficient distance between the sample and reference peaks, and 
> the same issue results even if no samples are loaded. CO2 on-offs are 
> fine, with a standard deviation of about 0.04‰. Does anyone know what 
> may be causing our disparity?
> Thanks,
> Rich Dabundo