Component of inductance $H_3$ of armour

3rd component of inductance due to armour steel wires.
For non-touching wires, $H_3$ is zero.

Symbol
$H_3$
Unit
H/m
Formulae
$0.4\left(\mu_t {cos\left(\phi_{ar}\right)}^2-1\right) \frac{t_{ar}}{d_{ar}}{\cdot}{10}^{-6}$
Used in