Thermal capacitance insulation, 1st portion (IEC 60853)

his corresponds to $\sigma\cdot{A_i}$

Symbol
$Q_{i,t1}$
Unit
J/(m.K)
Formulas
$\frac{\frac{\sigma_i \pi}{4} d_{c,t} \left(D_{i,t}-d_{c,t}\right)}{{10}^6}$