Dear Damodaran,
We are using clean air for VT, cooling and spinning as well as eject for
liquid as well as solid state NMR. For room temperature and above room
temperature upto 50 degree it is ok to use clean dry air.
We have been using clean dry air since last 20 years with varian 300 MHz
NMR spectrometer.
However, for low temperature and higher than 50 degree Celcius temperature
it is recommended to use Nitrogen to avoid freezing at low temperature and
to avoid oxidation of electronic components like capacitors and coil
contacts.
Regards.
L.S.Mombasawala.
NMR Lab,
SAIF,RSIC,IIT Bombay,
Powai, Mumbai 400 076
On Thu, 23 Jun 2005 22:03:33 +0200, Damodaran Krishnan
<damodak_at_muohio.edu> wrote:
> Dear friends,
>
> We have a serious debate at our department regarding the use of air
> or nitrogen for MAS and VT controls. Due to a reduction in our
> budget, we are trying to cut down the operation costs in all
> possible way. There is a huge difference in cost for using “Nitrogen
gas†(either from boil off or from N2 generator) compared to using
“clean dry airâ€.
>
> As far as I spoke to different NMR persons, everybody told me it is
> not a problem to use air for MAS and for VT for room temp expts. But I
have a hard time convincing one new faculty who somewhere got the idea
that air is harmful to NMR probes and HAVE to use Nitrogen gas.
>
> I finally decided to ask the AMMRL people, who are the NMR experts, to
help me make a decision whether to use “clean dry air†or nitrogen
gas.
>
> Thanks
> Damodaran
>
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Received on Wed Jun 29 2005 - 21:00:36 MST