UW CHEMISTRY NMR

As we all know, the DRX499 magnet takes involved effort to shim up to get usable lineshapes.  Duration of 24 hours or more for shimming all the 28 shims is not uncommon.   All this effort gets wasted when users inadvertently turn the wrong ‘knob’ under the magnet while they are trying to tune and match the probe with the ‘wobb’ command.  The picture above should give a clear idea.

USERS ARE REQUESTED TO DIRECT THAT FEW SECONDS WORTH OF ATTENTION WHILE TUNING/MATCHING SO THAT THEY DON’T LOOSEN THE PROBEHEAD FROM ITS DEFAULT POSITION.

Moving the probe by a fraction of a mm is sufficient to completely alter the shim gradient profile and render the optimized shim set useless.  It is in your own interest to identify the correct 1H Tune and Match knob and not touch the GOLD coloured knob.