Constant U for cables in ducts

According to IEC 60287-2-1 Ed.3.0 (2023)

Symbol
$U_d$
Unit
K.m/W
Choices
MaterialValue
PE1.87
PP1.87
PVC1.87
WPE0.1
Metal5.2
Fibre5.2
Earth1.87
Cem5.2