This invention relates to a device with function for measuring volumetric changes in a substance. In particular, the device with function for measuring volumetric changes in a substance comprises a sensor that detects the amount of light intensity produced by a light source aligned with said sensor when passing through a column of two liquids which are immiscible among each other contained in a transparent tube, wherein the sensor and the aligned light source are mounted on an arm that travels on a vertically arranged rail, wherein the arm is attached to a strap which acts by means of a first and a second pulley causing the movement of said arm, wherein the movement of said pulleys comes from a motor and a gearbox and the entire mobility system is mounted on a frame. The device further comprises data acquisition means which record the change of light intensity and control the arm movement.