At last week's AMMRL meeting, one of the discussion groups was on magnet
moves and facility planning.
Magnet moves:
This was mostly sharing anecdotes. The only real consensus was no
consensus.
Some people have moved magnets at field, even in a elevator, but this is
not recommended
If moving a magnet at field, know the path and any possible problems.
This includes metal door frames and door thresholds.
The informal feeling was that small, new (shielded) magnets could be
moved within the same floor of a building reasonably easily (at field).
Longer distances or bigger magnets should be not-magnets.
Moving them cold (or at field) requires care that bouncing doesn't snap
the brittle fiberglass spacers.
Older magnets should perhaps be warmed and serviced if they have to be
moved. There was no agreement on the dividing line. The older the
magnet, even if it does not have problems now, the more likely it will
someday, and the more sense it makes to do a servicing.
Given that most new magnets do not have power supplies or even sticks,
it may be necessary to hire a vendor or contractor. Make sure the
contractor has actually done this, and has all the necessary equipment.
Also make sure that the contract is very specific, and that the
contractor is insured and bonded.
Planning a new or renovated facility:
Windows! Even below ground it is sometimes possible to get something. Ask!
Measure the vibration and make plans to deal with it.
Ideally, no water sprinklers (esp. above the electronics).
Decide on putting your large magnet in a pit or not. In a pit- fills
are easier. But, changing probes or even tuning probes is a possible
problem. And flooding.
At floor level should reduce the chance of flooding, and make probe
tuning and change easier. But fills and sample changing will be more
challenging.
If you can convince your facilities to put the whole lab on one UPS, you
may be able to get them to do the maintenance. You will still have to
nag them about it. All UPSs need a bypass for when they break. Don't
forget to budget for the battery replacement.
If you use house air, get a digital (recording?) readout of the
dewpoint. So you can bug facilities about replacing filters and desiccant.
People with oxygen sensors generally do not like them. They are fussy
and fragile and finicky and other adjectives that start with the letter
f. In most labs, oxygen is not really an issue unless all the magnets
quench simultaneously. (The bottom of a magnet pit is one place where it
may be an issue.) If you have them, put them both low (nitrogen) and
high (helium).
Fight to be on the planning/design committee. Look at the blueprints
carefully. Ask lots of questions. Do you want a valve that needs
servicing right above the magnet? Do you want water pipes right above
the console?
kas
--
Karen Ann Smith Director, NMR Facility
Group Leader, Analytical Chemistry Services
Department of Chemistry and Chemical Biology
Clark Hall MSC03 2060
1 University of New Mexico Albuquerque, NM 87131-0001
karenann_at_unm.edu 505.277.4031 http://nmr.unm.edu
Out of this world screensaver: http://setiathome.ssl.berkeley.edu
"Something that has a one-in-a-million chance of happening...
happens once every second at 1 MHz."
Received on Tue Apr 24 2012 - 09:24:36 MST