In this work, a quartz resonator or QCM microbalance sensor system based on a phase detector circuit is implemented. Until now, the phase detection method in QCM sensors has been used for mass measurement applications. In this work, the system is characterized for its use in applications to measure the properties of a liquid (density and viscosity). In a first part, the implementation of the system is described. Once implemented, it is calibrated with solutions of increasing viscosities, obtaining the sensitivity equation and the resolution of the output voltage to changes over the square root of the density-viscosity product. Finally, the results are compared with those obtained by the authors in previous works using oscillator circuits and a network analyzer as electronic measurement interfaces.