A measurement device has two electrodes in the liquid forming a capacitor the capacitance of which depends on the height of the liquid, a microcontroller connected to an electrode and having a capacitance determination circuit for determining first and second values of the capacitance of the capacitor respectively during charging and discharging of the capacitor, an oscillator circuit for generating signals at a reference frequency when the electrodes are not connected to the microcontroller, then at a variable frequency dependent on the height of the liquid when the electrodes are connected to the microcontroller. The microcontroller further includes a programmable logic device configured into a comparator circuit, and a frequency determination circuit connected to the programmable logic device so as to determine the variable frequency from the reference frequency and from the signals of the programmable logic device.