Will a compass be effected by prolonged exposure to metallic objects? <br><br>

>>Will a compass be effected by prolonged exposure to metallic objects?<<<br><br>From my limited understanding of the physics involved, this seems very, very unlikely... I would think that even a magnet would be unlikely to affect it over long periods, so long as the needle/dial is free to rotate into alignment with the magnetic field. If you had a powerful enough magnet and the needle was not free, you could conceivably have a problem in time.<br><br>Of course, the compass has to be free of extraneous magnetic influences while operating. The only metals capable of this are iron (steel is an iron alloy), nickel, and cobalt (other metals can create eddy fields and such, but that's something else).. so, it's worth maintaining some minimal distance from these metals while using the compass. This has been a problem on occasion when the helmsman on a boat, standing behind the compass for hours, has a heavy knife in his pocket or on his belt, for instance. In the woods, hatchets and ax heads are a prime culprit- but I woudn't worry about permanent damage.<br><br>