Abstract
We have investigated the temperature dependence of the electrical parameters (permittivity and conductivity) of blood. The measuring system, composed of an impedancemeter (HP 4291A), an open-ended coaxial line and a temperature controlling set, was designed for dielectric measurement in the frequency range of 1 MHz to 1 GHz. Measurements were performed on ex vivo blood of humans and animals (cow and sheep). The results obtained show the weak sensibility and a change of sign of the temperature coefficient of the relative permittivity (about 0.3% °C−1 at 1 MHz and −0.3% °C−1 at 1 GHz). The conductivity presents a more significant variation (of the order of 1% °C−1) over the whole operating frequency range.