Ferite torroid problem

[boylesg]

What is the difference between the Al value on this page: **broken link removed** and the relative permeability on this page: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/indtor.html?

 

[FvM]

These are related, but different quantities. In the equation below, AL is L/N²



Equation copied from https://en.tdk.eu/blob/519704/download/2/ferrites-and-accessories-data-book-130501.pdf

 

[boylesg]

These are related, but different quantities. In the equation below, AL is L/N²



Equation copied from https://en.tdk.eu/blob/519704/download/2/ferrites-and-accessories-data-book-130501.pdf

How do you convert AL to k?