We present a novel sensor, combined with a new algorithm, which allows measuring the volume of growth of multiple defects inside an investigation area using only impedance information. The sensor is developed in low cost PCB technology and is used to validate the algorithm which estimates the volume of defects. The proposed method is simpler and faster with respect to Electrical Impedance Tomography (EIT); the low computational complexity allows the use for real time applications. In particular, we aim at the development of this methodology for the measurement of thrombus formation in artificial microchannels. The sensor has been characterized using glass microspheres and evidenced a non-linearity in volume estimation in the order of 1%.