the acoustic impedance of the drilling fluid may be found using reflections from a precise metal disk , and therefrom the density of the drilling fluid . because the reverberation characteristics of an acoustic wave depend in part on the acoustic wave shape , the first reflection from the metal disk may be used to calibrate the measurement . a method for determining a borehole fluid property is disclosed that includes generating an acoustic signal within a borehole fluid , receiving reflections of the acoustic signal from the fluid , and analyzing a reverberation portion of the acoustic signal to determine the property . the analyzing of the reverberation portion may include obtaining a theoretical reverberation signal and relating the measured reverberation signal with the theoretical reverberation signal to determine the borehole fluid property .