Measurement dielectric constant of new transformer oil at frequency 18 to 26 GHz (K Band): article / Nurul Elieya Che Muda

Abstract—Nondestructive, noncontact and real time evaluation of dielectric properties of low-loss liquids is important for applications such as service-aged transformer oil, biomedical, remote sensing and design of radar absorbing material. In this paper, present a method for measurement of dielectric properties of transformer oil using metal-backed method. Complex reflection coefficient (Su) is measured for Plexiglas container backed by metal plate. Dielectric constants and loss factor were measured for new and used transformer oil in the frequency range 18 to 26GHz (K-Band).The thru,reflect and line (TRL) calibration technique were used to eliminate the effect of undesirable multiple reflection. The dielectric constant foe new and used transformer oil sample is 2.1+ O.l.The loss tangent (tan 8) foe new transformer oilis 0.02 to 0.06 and for used transformer oil is 0.03 to 0.07.Loss tangent for new transformer oil is lower than used transformer oil