Calculating Magnetic field dimensions

[dwaring28720]

simple question which probably has a complex answer, if given the dimensions and composition or a permanent magnet ie if the magnet is a cube 10mm x 10mm N35 Neodymium where would one find the equation to calculate the range at which the magnet extended

 

[Bob S]

Here is an online field calculator for both round and rectangular magnets.
http://www.arnoldmagnetics.com/Content1.aspx?id=4621

There are others on the web. I don't know of where to find the equations.

Bob S

 

[dwaring28720]

works perfectly for my purposes thanks alot

 

[MagnetDave]

Just a freebie, since you mentioned my employer. Arnold also has an app for that. If you're on an iPhone, you can go to the App Store and get a free iPhone app that does that, too.

 

[sardar]

The equation to calculate the range at which the magnetic field of a permanent magnet extends can be found in the Ampere's Law formula, which states that the magnetic field strength at a distance r from the center of a magnet is equal to the permeability of free space (μ0) multiplied by the magnetic moment of the magnet (m) divided by 4πr^3. The magnetic moment of a magnet can be calculated by multiplying the magnetic field strength (B) by the volume of the magnet (V). In the case of a cube magnet, the volume would be (10mm x 10mm x 10mm) = 1000 mm^3. Therefore, the magnetic moment of the cube magnet would be B x 1000 mm^3. The range of the magnetic field can then be calculated by solving for r in the Ampere's Law formula. This equation can be further modified for different shapes and compositions of magnets, but the general concept remains the same.