Hi Clemens,
I also use dummy samples on two of the magnets without automatic sample changers.
The main benefit I've heard is it acts as a "dust cover" to protect the probe
from any debris that falls down the bore, though keeping the plastic covering
on top of the bst arguably offers the same protection. Personally, I like the
order of operations it forces my users into. I don't keep spare spinners laying
near the instrument station, the dummy sample has the only one. Users need to
first remove the dummy sample before they can position their research sample.
It makes them less likely to absentmindedly load samples into the magnet without
first activating/checking the eject gas. Users still find ways to surprise me
of course, but I prefer "idiot proofing" the routine procedure as much as possible.
Kind regards,
Luke
Luke Fulton, PhD
CHEM BLDG R003
NMR Core Facility Director
Unit 3060
COR2E & Department of Chemistry
55 N Eagleville Road
University of Connecticut
Storrs, CT 06279
email: fko24003_at_uconn.edu
(alias): luke.fulton_at_uconn.edu
mobile: (603) 953-5275
Office: (860) 486-4069
________________________________
> From: main_at_ammrl.groups.io on behalf of Steve Clemens via groups.io
> Sent: Wednesday, January 28, 2026 10:37 AM
> To: main_at_ammrl.groups.io
> Subject: Re: [AMMRL] dummy samples frequently get stuck in sample changer
I'm curious as to why you keep a dummy sample in the magnet when it's not in use.
Over the years I've had several samples go into the magnet with the lift gas
off. All but one of them landed without damaging anything: the backpressure
of the air in the bore coming past the spinner as it falls slows it down a lot,
and when the spinner enters the constricted part at the top of the shim tube
(lower part) the sample is aligned to the probe cavity (note: this is with
lightweight spinners like the blue POM or white Kel-F).
The one that did break went down when there was already a sample in the magnet.
It landed on top of the sample that was in there and broke. Luckily Bruker
designed the spinners such that they can hold the volume of a typical 5 mm
sample in the top so it didn't leak into the probe. Getting it out was the
challenge - I had to remove the probe and push it up from the bottom.
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#3171): https://urldefense.com/v3/__https://ammrl.groups=
.io/g/main/message/3171__;!!PvDODwlR4mBZyAb0!VL1tkZrm4ZKiayqZliCPOfqpdZhrSc=
RSF2LGmJNFVgyEQyis_cTwveiQm-PrXF9RhTh1pEU89IKfLFSIHzpFRxihbTeb$
Mute This Topic: https://urldefense.com/v3/__https://groups.io/mt/117474748=
/7559972__;!!PvDODwlR4mBZyAb0!VL1tkZrm4ZKiayqZliCPOfqpdZhrScRSF2LGmJNFVgyEQ=
yis_cTwveiQm-PrXF9RhTh1pEU89IKfLFSIHzpFR3kvuzE-$
Group Owner: main+owner_at_ammrl.groups.io
-=-=-=-=-=-=-=-=-=-=-=-
Received on Wed Jan 28 2026 - 08:12:26 MST