Hi everybody,
I'm looking for information about "MR grade" helium from Praxair (part#
HE6.0MR-T). The difference between normal grade 6 and MR grade 6 helium
is that normal grade 6 helium is batch-tested and then put into the
cylinders, while each cylinder of MR grade is tested for purity after
it's put into the cylinders. Each cylinder comes with a certificate
showing that the helium coming out of THAT cylinder really is grade 6.
I've mostly used MR grade for the last few years, but I've occasionally
gotten a normal grade 6 cylinder and used it. I've never noticed any
difference in the performance of the cryoprobe (or any purity issues
like the preamp heater power dropping quicker). I just called them to
order a cylinder and discovered that they've approximately doubled the
price. They're now charging $1429.09 for one cylinder. At that price I'm
wondering if it's really worth it.
Does anyone have any strong opinions about this?
thanks,
-Robert
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Robert Peterson, Ph.D.
Facility Manager - NMR Technology Center
UCLA-DOE Institute for Genomics and Proteomics
UCLA Dept. of Chemistry and Biochemistry
phone: (310)825-1816
fax: (310)825-0982
peterson_at_mbi.ucla.edu
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Received on Thu Oct 06 2011 - 13:59:31 MST