Australia's Science Forum

I have a question from our PDHPE faculty (and from me as well because I don't know the answer).
Often when we go to use the magnetic compasses they need to be reminded which way is north.
I know how to do that (from Chemtalk of course) but the question is: Is this happening because of the way we store them? Is there a way to prevent this happening?
If anyone has a solution we would be most grateful to know about it.
Thanks
J

If you are storing them near anything magnetic or an electric motor, even a dishwasher or fridge, it will affect them.
Also the fridge magnets will affect them.

It is possible for the magnetic needle to lose its polarity. Compass should be stored away from electronics (e.g., GPS, radios), batteries and many metallic (knives, saw) objects. Store away from magnets

Thank you for that. The PE teacher was wondering if storing 20-30 of them together may effect them. We know to store them away from magnets etc. but can they have a negative effect on each other?
J

J wrote:Thank you for that. The PE teacher was wondering if storing 20-30 of them together may effect them. We know to store them away from magnets etc. but can they have a negative effect on each other?
J

Not noticably. Compass needles are fairly low strength magnets. The problem is with strong fields perpendicular to the plane of rotation (so the needle can't swing into alignment).

Thanks again for the help.
I hope the next time the PE teacher brings down compasses to be sorted out I'll be on long service leave and he'll have to deal with it.
J

Perhpas this should be seen to be "regular maintenance".