A method for locating and quantifying obstructions in a pipe is described. The method comprises the steps of emitting at one end of the pipe, by means of a loudspeaker, an emitted signal comprising a wave train at a first frequency, the waves being of an acoustic type; receiving at the same end of the pipe, by means of a microphone, a reflected signal, resulting from the reflection of the wave train from obstructions in the pipe; determining a position of each of the obstructions according to a delay measured between the wave train of the emitted signal and the wave train of the reflected signal received by the microphone; and determining, for each of the obstructions, its degree of obstruction by extrapolating the energies of the emitted, reflected and transmitted signals. A system comprising the loudspeaker, the microphone, a processor, and a memory for performing the above method is also described.