Component of inductance $H_3$ of 2nd armour

Third component of inductance due to second layer armour steel wires. For non-touching wires, $H_3$ is zero.

Symbol
$H_{3_{2}}$
Unit
H/m
Formulae
$\frac{1.0 \cdot 10^{-6} d_{f_{2}} \left(0.4 \mu_{t} \cos^{2}{\left(\beta_{a_{2}} \right)} - 0.4\right)}{d_{a_{2}}}$
Related
$\beta_{a_{2}}$
$d_{f_{2}}$
Used in
$B_{1_{2}}$