We reviewed the electronic principles and design of the wire-mesh sensor with respect to inherent energy losses. From the analysis we derived a new circuit design with an optimized amplifier circuit and extended the sensor by an extra transmitter electrode embedded into the dielectric construction material. The latter allows an inherent determination of the energy losses that cannot be suppressed by circuit optimization only. Experimental analysis showed that we achieve an improvement in measurement accuracy with respect to the local and average phase fractions. Deviations in a single crossing point are reduced from more than 30% down to less than 5% and deviations in the average phase fraction are reduced from more than 15% down to less than 2% .