Electrical resistance of armour

Symbol
$R_{ar}$
Unit
$\Omega$/m
Formulae
${10}^6\frac{\rho_{ar}}{A_{ar}}$at 20°C IEC 60287
${10}^6\frac{F_{lay,ar} \rho_{ar}}{A_{ar}}$at 20°C Cigre TB 880 GP 32
$R_{ar} \left(1+\alpha_{ar} \left(\theta_{ar}-20\right)\right)$at operating temperature
$f_{ar} R_{ar} \left(1+\alpha_{ar} \left(\theta_{ar}-20\right)\right)$magnetic steel wires at operating temperature AC