Parameter m of armour

Definition according to Cigré guide 531 chapter 4.2.1.

Symbol
$m_{e67}$
Formulae
$\sqrt{\frac{\omega \mu_0}{\rho_{ar}}}$armour
$\sqrt{\frac{\omega \mu_0}{\rho_{sp}}}$steel pipe
Used in
$z_{ar,i}$
$z_{ar,m}$
$z_{ar,o}$