Operating range for the Fluke handheld temperature calibrator?
-Ravi
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From: Plant,Daniel [dan_at_mbi.ufl.edu]
Sent: Tuesday, February 17, 2015 12:33 PM
To: 'Rajan Paranji'; AMMRL
Subject: RE: AMMRL: back to the basics...another helium question
But if it’s -153, isn’t most of the dripping from O2 and N2?
Or am I missing something…
Dan
From: Rajan Paranji [mailto:paranji_at_chem.washington.edu]
Sent: Thursday, February 12, 2015 5:49 PM
To: AMMRL
Subject: AMMRL: back to the basics...another helium question
Dear All
Hope it doesn't hurt to visit the basics and ascertain 'facts' to remain so. During Helium fills, we are all familiar with seeing the dripping droplets from the manifold. Over the years I have been fuzzily convincing myself that this condensed O2 or N2. Today, I stuck a thermocouple in a suitable spot in the manifold and connected the same to a Fluke handheld temperature calibrator and found that the lowest temperature reached was -153 degree C i.e. approx. 120 K.
Liquid O2 boiling point is approx. 90.1 K and LN2 is 77 K. The drip happens on the outer surface of the Helium manifold so evidently it is condensing something from the atomosphere in the room. So, what is this liquid ?
Thank you, as always, for indulging my naivete. Hope to see most of you at the ENC in Asilomar !
Best Regards
Rajan
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____________________________________
Rajan K Paranji, Ph.D.
NMR Facility Manager
Department of Chemistry
Room 65, Bagley Hall
University of Washington
Seattle, WA 98195
*ph: 206 685 2581
fax: 206 685 8665
email: paranji_at_chem.washington.edu<mailto:paranji_at_chem.washington.edu>
____________________________________
Received on Thu Feb 19 2015 - 05:28:25 MST