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Thanks, Matheus.

I've got an older GCC III that I have to manually adjust.

So, if I do a series of on/offs, 8 refgas peaks, of increasing size from 1
V to 10 V I get a much smaller effect of ~ 0.3 permil/V with an H3 of ~ 3.2
applied. This same H3 is applied to my alkane standards, but I still have
the effect I described above.

Grumble...




On Mon, Jan 16, 2017 at 4:33 PM, Matheus Carvalho <
[log in to unmask]> wrote:

> Jeff, in my case Isodat changes automatically the peak sizes. I am using
> Conflo IV. Maybe you are using an older Conflo?
>
> Matheus C. Carvalho
> Senior Research Associate
> Centre for Coastal Biogeochemistry Research
> Southern Cross University
> Lismore, NSW, Australia
> 61-4-8899-0092
>
> Editor of HardwareX (Elsevier): http://www.journals.elsevier.com/
> hardwarex/editorial-board
>
> Book: Practical Laboratory Automation Made Easy with AutoIt
> http://www.wiley-vch.de/publish/en/books/ISBN978-3-527-34158-0/
>
> YouTube channel: http://is.gd/lab_automation
>
> On Mon, Jan 16, 2017 at 11:54 PM, Jeff Salacup <[log in to unmask]>
> wrote:
>
>> Hi Matheus,
>>
>> Well, I manually change the size of the refgas peaks during the H3
>> sequence. To do what you suggest, would I do a series of on/offs and change
>> the refgas peak size there? Would the H3 correction be applied to this data?
>>
>> Also, "when I do the H3 correction"... isn't the H3 correction something
>> ISODAT automatically does once you perform and save an H3 sequence?
>>
>>
>> Thanks!
>>
>> On Sun, Jan 15, 2017 at 5:43 PM, Matheus Carvalho <
>> [log in to unmask]> wrote:
>>
>>> Do you see the same effect by manually changing ref gas peaks
>>> intensities? By checking this you can evaluate if the problem is in the
>>> standards or in the sensor. Also, When I do the H3 factor correction it
>>> gets really good. So maybe you should try again...
>>> Good luck,
>>>
>>> Matheus C. Carvalho
>>> Senior Research Associate
>>> Centre for Coastal Biogeochemistry Research
>>> Southern Cross University
>>> Lismore, NSW, Australia
>>> 61-4-8899-0092
>>>
>>> Editor of HardwareX (Elsevier): http://www.journal
>>> s.elsevier.com/hardwarex/editorial-board
>>>
>>> Book: Practical Laboratory Automation Made Easy with AutoIt
>>> http://www.wiley-vch.de/publish/en/books/ISBN978-3-527-34158-0/
>>>
>>> YouTube channel: http://is.gd/lab_automation
>>>
>>> On Mon, Jan 16, 2017 at 9:33 AM, Jeff Salacup <[log in to unmask]>
>>> wrote:
>>>
>>>> Hi Isotopers,
>>>>
>>>> Me again.
>>>>
>>>> I've got a Thermo Trace GC Delta V Advantage running leaf wax dD. I do
>>>> daily H3 corrections - averaging ~3.2 permil/V. However, if I run a
>>>> dilution series of our standards I still get a powerful peak size effect:
>>>> r2 always greater than 0.9 and slopes of ~ 1-2 permil per V for a dynamic
>>>> range from 2-20 V. We do aim to have our unknown peak sizes all very close,
>>>> but I'd still love to get rid of or control for this effect.
>>>>
>>>> Any thoughts?
>>>>
>>>> Thank you, once again, for any wisdom imparted!
>>>>
>>>> --
>>>> Jeff
>>>>
>>>>
>>>>
>>>>
>>>> *Two things are infinite: the universe and human stupidity; and I'm not
>>>> sure about the **universe. - Einstein*
>>>>
>>>>
>>>>
>>>>
>>>> *__________________________________________________________________**Jeff
>>>> Salacup, Ph.D.*
>>>> *Stable Isotope & Biogeochemistry Lab Manager*
>>>> *UMass-Amherst*
>>>>
>>>>
>>>
>>
>>
>> --
>> Jeff
>>
>>
>>
>>
>> *Two things are infinite: the universe and human stupidity; and I'm not
>> sure about the **universe. - Einstein*
>>
>>
>>
>>
>> *__________________________________________________________________**Jeff
>> Salacup, Ph.D.*
>> *Stable Isotope & Biogeochemistry Lab Manager*
>> *UMass-Amherst*
>>
>>
>


-- 
Jeff




*Two things are infinite: the universe and human stupidity; and I'm not
sure about the **universe. - Einstein*




*__________________________________________________________________**Jeff
Salacup, Ph.D.*
*Stable Isotope & Biogeochemistry Lab Manager*
*UMass-Amherst*