In this paper, an electronic system designed to measure the frequency shifts in an experimental AC electrogravimetry setup has been presented. This system is committed to acquire appropriated data for determining the electrogravimetric transfer function (EGTF) and provide information regarding the mass transfer in an electrochemical cell in the AC electrogravimetry technique, but maintaining a good trade-off between the locking frequency bandwidth and the resolution in the frequency tracking. The system is based on an analogue-digital phase locked loop (A-D PLL). The achieved results prove the system reliability to conduct the fast, continuous and accurate frequency shifts measurement under experimental condition in AC electrogravimetry.