Flux density B

The flux density is the number of magnetic field lines that pass through a certain point on a surface. Another indication is magnetic induction. The unit of magnetic flux is the weber (Wb).

The SI unit is T (tesla), which is equal to weber per square metre (Wb/m2). The unit in the CGS system is G (gauss). 1 tesla is equal to 10,000 gauss.

At any given point in a magnetic field, you can see the magnetic flux density as a vector in the field direction with a magnitude equal to the Lorentz force that an electrical wire experiences when it is oriented perpendicular to the field lines.

The higher the flux density, the stronger the magnet is at that point and therefore the better it can hold iron particles at that point.

In a homogeneous field where the surface is perpendicular to the magnetic field lines, it is the product of the surface and the magnetic field strength. Magnetic flux density is usually represented in formulae with the symbol, a (pseudo) vector field.

FluxΦ = B·AΦ = magnetic flux (Wb)
B = magnetic field strength (T)
A = surface (m2)

Goudsmit calculates the flux density using the Finite Elements Method (FEM calculation). This allows us to develop the right magnet for a new or existing product or application, faster and better. You can read more about magnet calculations and simulations here. Or you can read our whitepaper on this subject.