First component of inductance due to first layer armour steel wires.
For steel tape armour, the length of lay $p_a$ is assumed to be equal to the mean diameter of the frist armour layer $d_{a_1}$.

Symbol
$H_{\mathrm{1}}$
Unit
H/m
Formulae
$\frac{1.0 \cdot 10^{-7} \mu_{\mathrm{e}}}{d_{\mathrm{a_{\mathrm{1}}}} p_{\mathrm{a_{\mathrm{1}}}}} d_{\mathrm{f_{\mathrm{1}}}}^{2} n_{\mathrm{a_{\mathrm{1}}}} \pi \sin{\left (\beta_{\mathrm{a_{\mathrm{1}}}} \right )} \cos{\left (\gamma_{\mathrm{a}} \right )}$
Related
$\beta_{\mathrm{a_{\mathrm{1}}}}$
$d_{\mathrm{a_{\mathrm{1}}}}$
$d_{\mathrm{f_{\mathrm{1}}}}$
$\gamma_{\mathrm{a}}$
$H_{\mathrm{1_{\mathrm{2}}}}$
$\mu_{\mathrm{e}}$
$n_{\mathrm{a_{\mathrm{1}}}}$
$p_{\mathrm{a_{\mathrm{1}}}}$
Used in
$B_{\mathrm{1_{\mathrm{1}}}}$