How to measure magnetic field of a magnet

[Cspeed]

I have a cylindrical neodymium magnet. I know that the magnetic field varies with distance, but how would I determine the magnetic field B at a certain point, through experimentation? I know how to find the force between two magnets at different distances by balancing out with gravity, but I'm stuck as far as measuring fields. Is there an equation which can relate fields and forces for magnets?

 

[f95toli]

If you want an accurate value you will need to measure the field using e.g. a Hall probe.
Instruments used to measure absolute magnetic field are often called Gaussmeters.
They are however quite expensive.

(a more general name for this type of instruments is magnetometer, although that name can also refer to instruments that measure changes in the magnetic field or relative fields)

 

[Cspeed]

Then I guess there's no way to do it economically/creatively? What if MacGuyver only had some duct tape, a paper clip, and a magnet and needed to find out the B?

 

[prince7]

i know that this replay is too late but i have a solution for this
u can build ur own gauss meter with very law cost
if u want to know visit this website
http://www.coolmagnetman.com/magmeter.htm