Smartphones measure magnetism in 3D?!?

I would not put an expensive phone near a large magnet. There is a risk of inducing currents and/or permanently magnetizing parts of the phone that could mess with its function. So far my own phones have recovered fine after being maxed out several times, but there's no guarantee that any phone will ;)

I had heard somewhere that one needed to be cautious with bringing your phone near a strong magnetic field as it could damage the ability to accurately act as a compass afterwards. Any concern there?

Joe Tomasone

I believe it technically should be possible. At least for an estimate What I need to check first is how accurate it is at higher readings. Is 3000 microtesla on the phone also 3000 microtesla on a gauss-/teslameter? I guess it is accurate up to 4900 microtesla but since it is only meant for measuring the Earth's magnetic field between 20- 65 microtesla it may not be that optimized at higher readings. Measuring magnets at a distance is not ideal unless you need the magnet to do something at a distance - the gradient is changing very fast with distance. I think it is more like distance cubed due to the dipole nature - but that could be the main topic of a video where I test magnets at distance with a smartphone ;) Thanks for the input, Boots!

I would be curious to know if it was possible to still use the phone to at least get a good estimate of a larger magnets strength by kind of "calibrating" it. What I mean is to use the fancy meter at a fixed distance away and comparing it to the phone reading. Field strength uses distance squared, right? That means it wouldn't necessarily be a straight multiple, but could you get a conversion that would be close enough to be useful? I also wonder if you could use the phone for larger magnets if you hold it at a fixed distance and compare it to a magnet of known strength. These are the just the things that I thought while I was watching the video. Awesome video as usual!

The Boots