as it turned out the vendor contracted the whole package to oxford. their
policy, as i understand it, is to "warm" up the magnets, even though one
of our magnets (300Mhz) was moved just 20 feet. they implied that inspection
and "da kine" was necessary in our case ( 300Mhz magnet-vintage 1984 ).
if you are relocating your magnets to make space for a new nmr system, this
is one alternative you might consider.
one caveat to be considered is that ( at least on our system) the supercon
shims on the bruker acf-250 had to be adjusted to resolve h2o to at least
8 Hz otherwise the room temperature shim on z2 would run out of range!!
neither oxford nor i knew of this, and brand "B" either wasn't talking or
forgot to mention it to me somewhere along the line. the bottom line is
to make sure you are within an eyelash of the supercon shim current values
taken during the original installation, especially z2, if you start with
a "warm" magnet. the oxford engineer had to supercon shim three times
before i could acheive .5Hz resolution on h2o. initially he stopped at
26Hz (all room temp shims zeroed), and i ran out of z2. at 15Hz i also
ran out of z2. oxford had to supercon shim our system to 7Hz in order
keep the z2 room temperature shim setting reasonable. this was not the
case with our GE (sic) system. at 25Hz (supercon) i was able to suck in
.5Hz resolution on our GN-300 with little difficulty.
jim loo