some of you may remember that in the
last week of january, i posted help for air dryer failure
and got oodles of good help from over a dozen people who
responded.
subsequent to this, some of our 6 spectrometers that were
affected by the air dryer have been having various problems,
mostly due to water in the system not being properly
purged out, i think.
on systems with old FTS immersion baths, i thawed out the
cold finger and blew dry air through them and they were
fine. units with bruker's BCU05 seem to chug along fine
without any "cleaning".
i have one amx600 with a haake air chiller that seems to
be having alot of problems, however.
for one thing, the air pressure ball valve regulator on the
face of the vtu2000 seems to be rattling up and down quite
turbulently, and even at low vt air pressures i am seeing
major low frequency vibrations on the proton 90% water spectrum
at low receiver gains. (this unit used to have rock steady
pressure regulation before)
at anything close to the previous operating vt air pressures
i am seeing loss of signal and nothing but intense low frequency
noise glitches in the center of the spectrum.
i see that at this pressure the tuning dip also seems to be
unstable, and sometimes probe mismatch occurs during pulsing.
(for some strange reason the problem of tuning instability seems
worse with vt current on than off, but then here i may have a
different problem related to an old/worn vt heater wire/connector)
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my question to you all is:
after introduction of water into your spectrometers,
what is the best way to purge the water from your system?
i don't mean just for the immersion baths or the chillers
since the problem i'm seeing seems affect most badly the
vt controller unit and its pressure regulation.
thanks much in advance for all your help.
sincerely,
john chung
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Manager, NMR Laboratories (619)784-7453 (Office)
Dept. of Molecular Biology, MB2 784-7455 (Lab)
The Scripps Research Institute 784-9822 (Fax)
10666 N. Torrey Pines Rd. email: chung@scripps.edu
La Jolla, CA 92037 http://www.scripps.edu/~chung
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