Hi all! I’ve reached out to a few of you, so apologies if this is redundant.
For my research, I will be using a lot of NMR. The NMR lab is a small room with 4 machines, only 2 of which are shielded. The lab managers are explicit that you shouldn’t even enter if you have a pacemaker, for instance. I am equally concerned about the machines, and everyone’s results, as I am about my finger. These machines are up to $1 mill a piece and data is priceless. The managers wanted me to reach out to see if others have experience with this (being NMR + finger magnet) to help shape my decision as to how I proceed.
Do you currently have a finger magnet installed, or are you just considering getting one?
If I were you I would not enter that facility with a finger magnet. Similar to an MRI, an NMR spectroscopy machine generates extremely intense magnetic fields. Like an MRI they utilize superconductors which must be cooled to an extremely low temperature and cannot be turned off for the life of the machine.
While you may only feel a small tugging sensation from the “safe” distance of the control room, it’s very easy to absentmindedly approach the machine and it would likely injure you. Since NMR machines measure the vibrations of individual atoms, there’s also the possibility a “nearby” magnet will affect the accuracy of the measurements.
Hi! I’ve had one installed since 2016. Do you happen to know about how far from the sample tray the magnetic field begins to decline? I went within 4 feet of it, but don’t really want to play around with going any closer until I know for sure whether it would be safe. Do you think that I would be okay if I tightly wrapped it? This will really set me behind if I’m unable to use the NMRs at all.
Mu metal gloves? I’ve got nothing…
As far as I know there is no real way to shield something like a magnet in such a powerful magnetic field.
Have you found out where the 5 gauss line is? (should be drawn on the floor).
Crossing it can cause ferromagnetic material to go missile (at least near MRI, and I imagine NMR isn’t much different), and as you can imagine, having a magnet embededd near your tactile nerves tear its way out of your flesh and fly off at high speed is probably a very unpleasant experience (not to mention potentially an very very expensive repair job).
“Specifically, the “force” with which the ferromagnetic object is attracted to the center of the magnet is directly proportional to the intensity of the static magnetic field (B0), to the mass of the object and, inversely proportional to the distance cube.” Source, you should be able to calculate it from here.
I do not wish to scare you but know that the risks are very real.
I would personally have it removed if I wanted to work with these machines (you could always have it put in again later [it would suck, but losing valuable lab experience would probably suck more], you could even replace it with a Titan ).
This is also something to highlight, force potentially pinching your skin against the outside like that can kill your skin cells unbelievably quickly (I have heard the figure 20 minutes tossed around). And then your skin cells would die off in a couple of days, and your magnet just pop out of its encapsulation, leaving behind just a very nasty scar amd a very real risk of infection.
Take everything I say with a heaping teaspoon of salt and do your own research
Hmm. Do you know what type of encapsulation it has (silicone, parylene, TiN, PMMA)? 4 years and change is a really long time for a magnet, you might need to get it removed anyway. Do you get any tenderness from pressure in the area, or like a dull throb sometimes?
Regardless, it depends on the type of machine. I don’t think you or I know enough to test whether it would be safe. You may need a technician to tell you. If you could provide a manufacturer and model number for the specific machine(s) you’re using we may be able to look up the technical specs and tell you.