Abstract
ATM010 cavity with special heating equipment that permits measurements of the dielectric properties of unvulcanized rubber and polyethylene compounds is described. The measurements are performed at about 2800 MHz at elevated temperatures. An excellent agreement was found between dielectric constant and loss factor of standard liquids as predicted from perturbation theory and corresponding values calculated from shifts of resonant frequency and Q-value of the cavity. Measurements on different polar and non-polar rubber and polyethylene jcarbon black compounds are presented and the results and accuracy are discussed.