Abstract: Surfaces from which the ultrasound is reflected, very often are not flat. Therefore, in these surfaces there exist scatterers of ultrasound waves that prevent measurements. Nevertheless, on the other hand, scattered waves can be successfully used for measurements. For instance, obtained results from measurements with scattered waves, show that it is possible to make a comparison between the unknown volume with a given volume, taking the sum of the product of the squares of amplitudes of impulses of pressure or the sum of intensities and time increments of given volumes. The method of echo-systems of oriented waves is more complicated than the method with non-oriented waves (scattered waves). Therefore, here it will be shown the possibility of the use of the systems with non-oriented waves, in order to determine the volumes of systems with a regular or at least approximately regular geometry.