Resistivity, linear function of T

Presentation

This model defines a resistivity ρ as a linear function of the temperature for an isotropic or anisotropic material.

Mathematical model

Resistivity is a linear function of the temperature.

The corresponding mathematical formula is written:

ρ (T)= ρ_a(1+a(T - T₀))

where:

• T₀ is the reference temperature [degree]
• ρ_a is the resistivity of the material at T₀ [Ω .m]
• a is a coefficient (positive or negative) [degree^-1]

The shape of ρ(T) curve is presented in the figure below.

Anisotropic material

For an anisotropic material, this linear model consists of a group of three straight lines.