Hi,
I'd carefully listen for the air flow sound by putting my ear near the bore
when the lift is turned on. Get used to the sound level when the lift is
normal. When a sample next rockets out, leave the lift air on and try to
tell whether the air sound is more forceful. If the sound is the same, then
it's likely a mechanical sticking problem like Jacobsen & Paranji mention.
If it is noticeably louder...
I've seen high/low behavior like this associated with bad probe sealing on
Varian systems, which can let air leak past the probe and mimic pressure
reduction. You can turn up the air flow to overcome the problem, but later,
if you manage to get a good seal, there's too much air and it's
darts-in-the-ceiling time. You can test this by listening to whether the air
flow sound changes when you jiggle on the probe or stack. Solution, of
course, is to reseat the stack on your probe.
There might also be some kind of solenoid lift valve malfunction.
Best luck - Gerry
-----Original Message-----
From: transplatin_at_gmail.com [mailto:transplatin_at_gmail.com] On Behalf Of Ken
Knott
Sent: Friday, August 31, 2012 8:52 AM
To: ammrl_at_ammrl.org
Subject: AMMRL: Samples ejecting (like missiles) from magnet
Hello everyone..
In our Agilent MR400 system we have an occasional but increasing issue.
Every once in a while, sometimes once a week, sometimes twice in a day,
samples will literally fly out of the bore to crash on the magnet and
eventually shatter on the floor.
Nothing has changed in the gas regulators in the console nor the air
regulators feeding the console. They are all set as they have always been.
It seems as if something is getting stuck, pressure builds, and releases
suddenly upon eject...
Has anyone come across an issue like this?
Thanks,
Ken Knott
Assistant NMR facility manager
Virginia Tech
540-231-8256
Received on Thu Sep 13 2012 - 11:37:37 MST