Measuring Magnetic Field Strength of a Cylindrical Magnet

AI Thread Summary
The discussion focuses on quantifying the magnetic field strength of a cylindrical magnet, particularly in the transverse direction. While equations for the longitudinal field are available, the complexity of calculating the transverse field is highlighted, especially due to the finite nature of the magnet and its edging effects. Users reference Wolfram Alpha for insights but note that the calculations are intricate and suggest a numerical approach. At significant distances from the magnet, the magnetic field strength behaves like 1/R^3, indicating a dipole-like behavior. Overall, the challenge lies in accurately modeling the magnetic field due to the magnet's finite dimensions.
PhDnotForMe
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Hello,
Today I am wondering if anyone can help me quantify the strength of the magnetic field created by a permanent cylindrical magnet. I have been able to find equations online for the strength of the field within the z axis, (ie. the longitudinal length) but I would like to know the strength of the magnetic field in the transverse direction, or the strength of the magnetic field in the outward direction rather than on top or below.
 
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Pythagorean said:
A cylindrical magnet is finite and, therefore, has edging effects. It's not a straightforward calculation, but Wolfram Alpha briefly touches the calculation superficially (and notes that the guts are complicated) favoring a numerical approach.

http://demonstrations.wolfram.com/MagneticFieldOfACylindricalBarMagnet/
Thanks for that great reference. The equations listed are pretty intense. If you considered a point in the transverse direction REAALLY far away, and the length and diameter of the magnet are small in comparison, would the strength of magnetic field be roughly proportionate to 1/R^2? 1/R? 1/R^3? The integral listed in the reference is way to difficult for me to estimate the macro-behavior.
 
At a very long distance (compared to the extension of the magnet) you can use the leading-order multipole, which in this case is a dipole. The magnitude goes like ##1/r^3##.
 
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