[jtrout19]

Anyone ever heard of this stuff or have any experience with it? Would it be applicable in our hobby?

https://en.wikipedia.org/wiki/Mu-metal

[Mateusz]

It is for redirecting low frequency or static fields such as earth magnetic field. The only way to really isolate from magnetic field is by a few meters concrete wall. This works by redirecting it. Besides you don't want to distort static fields which is what you want to measure by magnetometer. Bad idea for magnetometer I would say.

[jtrout19]

Well fair enough.

[Mateusz]

Don't get me wrong, I am just not convinced it would be more effective then twisting horizontal high-current wires and mounting mag far where field is weaker.
There are however people who claim NU-metal helps "somehow", but I am sceptical and it could be different reason why it works for them. For example if you jam noisy magnetometer then for sure you get less noise but also less signal.

First attachment is the example how magnetic field propagates when wires are not twisted. If you twist your wires your field is "redirected" more flat, and gets redistributed in the direction twisted wires are going (see second picture of solenoid).

There are plenty of examples on internet. I also don't think twisting cancels magnetic field (maybe induced current). For example if you play with two magnets they either repel or attract to eachother but it does not cancel magnetic field. So the only thing you can do, is redirect that field to make it weaker in the direction which is hitting magnetometer and have magnetometer located 10-12cm above.

Hope that helps

[marts]

Hi Jtrout19. I work in magnetics. What is your application? I thought that one day I would install one of my magnetometers on my quadcopter. Localised magnetic field from motors generally drop off on a 1/r³ law so a small boom may be necessary depending on what resolution you are trying to achieve.
I put one of my magnetometers on the back seat of my car and drove 100 of k's through the countryside. The magnetic signature of the large scale geology was very predominant. Similarly on a quad a well placed magnetometer may work well as a metal detector (stony-iron meteorites) or for mapping some local geology (small impact crater).