Patent ID: 7426866

Claim:
A method for acoustically measuring one or more fluid parameters comprising: propagating a test waveform from an acoustic transducer through a liquid contained in a container and towards a free surface of the liquid, the test waveform comprising a short burst of acoustic energy generated by a piezoelectric crystal positioned at a proximal end of the acoustic transducer that is focused by a lens positioned at a distal end of the acoustic transducer; generating a step reflected wave by reflecting a portion of the test waveform off a calibration surface positioned between the acoustic transducer and the free surface, the calibration surface being positioned at a known distance from the lens; determining a first period of time that corresponds to the time interval for the step reflected wave to travel from the lens to the calibration surface and back to the lens; and calculating a sound velocity in the liquid by using twice the known distance of the calibration surface from the lens and the first period of time.