Traverse relative permeability of steel wires

The traverse relative permeability of steel wires depends on the particular sample of steel. The used value is an average value for wires of diameter from 4 to 6 mm.

We consider round and flat wires touching if they cover more than 95% of the mean circumference. which is calculated separately for the two armour layers

Symbol
$\mu_{t}$
Formulae
$10$touching wires
$1$wires not touching
Used in
$H_{3_{1}}$