Inspired by the thread: What would a magnet do to my laptop?
I’m not an expert on EMFs or anything, but aren’t MRI machines just about the biggest man-made EMF producers? How can we run such strong magnetic fields near all of the expensive/super-sensitive computers/machines.
You can’t wear jewelry/wristwatches/etc. around them because it has enough power to rip them off your body, your arm/skin in the way being of little consequence to the EMFs. At least that’s what I’ve heard.
So how does something putting out those kind of EMF waves, around ALL the sensitive medical equipment within the same building, NOT damage the computer monitoring equipment?
I’m guessing that they have a lead shield or something, but I don’t know if lead blocks EMF’s.
Sorry for rambling, but any opinions to enlighten me are much appreciated.
I realize that the answer has been obtained, but I thought I’d add tuppence. The faraday cage at my hospital’s MRI had gone bad - we could tell because the images were getting degraded, due to random radiowaves being received by the MRI. One of the cheap ways to test for field integrity is to go into the MRI suite with a portable radio - If you get a station, your faraday cage has gone wonky.
The strong magnetic field in an MRI is pretty much static, and Faraday cages don’t block static magnetic fields well. From the linked article:
I suspect the main “shielding” is just distance from the machine. The fields will fall off as 1/r^3.
Presumably, an MRI machine needs the Faraday cage to block RF fields from interfering with its operation.
I’d guess there are doors that have to be closed to complete the cage, and that they have contacts that are corroded, or bent. Either that, or seams (maybe where walls meet) have come loose.
It starts off with hanging around the pool hall drinking beer, then turns to marihuana, or “weed”, which is the gateway to “hard stuff”.
The main protective aspect of the magnetic field is in fact distance, and the cage is primarily to prevent RF interference, as mentioned above. In our case, the MRI suite is in the periphery of a much-remodeled building which has had multiple leaks and such. I suspect that it was leaks and corrosion, as they had to rip out most of the walls - around the massive magnet - and rebuild them. They upgraded the magnet while they were there.
An unrelated idea for a movie:
Tony Soprano type gets part interest in a private MRI clinic. He builds a secret room behind the magnet, within the faraday cage, so he can use it as a safe discussion room. All remote EM transmissions are blocked by the cage, magnetic tape is made useless by the magnetic field.
When the bad guys come to kill him, he breaks through the false wall into the MRI suite, and hilarity ensues. Patient runs for its, pistols get sucked into magnet bore, steel jackets slugs curve into the magnet, liquid nitrogen goes squirting around.
If you make the movie, just say “Thanks, Attack from the 3rd Dimension”.
