# thermal conductivity

thermal conductivitynoun

A measure of the ability of a material to allow the flow of heat from its warmer surface through the material to its colder surface, determined as the heat energy transferred per unit of time and per unit of surface area divided by the temperature gradient, which is the temperature difference divided by the distance between the two surfaces (the thickness of the material), expressed in watts per kelvin per meter.

## thermal-conductivity

Noun

(*plural* thermal conductivities)

Usage notes

The heat (thermal energy) flow *P _{th}* through a plate made of a given material depends on the thermal conductivity

*Î»*of that material, the surface of the plate

*A*, the temperature difference over the plate

*Î”T*and the thickness of the plate

*d*, and follows the formula:

Thus, the higher the conductivity, the higher the heat flow. The unit of thermal conductivity in SI system of units is WÂ·m^{-1}Â·K^{-1}.