FYI-

I have been working (as I know others are too) on locating a CO reference
gas. So far my search keeps sending me back to Messer (MG Industries in the
US) which has the cleanest CO I have found.  According to the folks at
Messer they can certify the CO for isotopic composition, but at an add'l
cost. This really isn't necessary but seems to be the 'only' way to get a
CO in the desired range needed for our work.

So my questions are directed to those that are using Messer CO MG4.7:

1. Have you found it necessary to have the isotopic composition
predetermined before purchasing the gas?

2. If not, is there a lot number you request for the CO of a certian
isotopic composition?

3. Or, is there really just one type of MG4.7 CO and the isotopic
compositon is approx the same from tank to tank?


Sorry to bring this issue up all over again, but some add'l info would help
me out.

Thx

Dave
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David A. Mucciarone
Laboratory Manager
Stanford University
Department of Geological and Environmental Sciences
Building 320, Room 118
Stanford, CA 94305-2115
650-723-0817 (office) 650-725-2199 (fax)
Office - Green Earth Sciences Rm. 331
Stanford Stable Isotope Laboratory - Green Earth Sciences Rm. 332 & 334.
e-mail: [log in to unmask]
WWW: http://pangea.stanford.edu/isotope/dam
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