The Speed of Sound in various liquids will vary, according to its temperature, pressure, density and cavitation.
One method might be, to get hold of an Ultrasonic Cleaner. Stick an additional Piezo electric transducer onto one side. Single pulse the Cleaner, with both transducers connected to a very fast dual trace Oscilloscope. Thus measuring the pulse/echo return.
A more simplistic idea would be:-
Stick two piezo transducers into opposite ends of a long glass tank. To prevent pulse/reflective overlap (for ease of measuring) use the shortest pulse possible. Simply discharging a small capacitor into your 'transmitting' transducer might work?
Get your University boffins to help out, it could turn out to be an interesting project.

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"You will never find a real Human being - Even in a mirror." ....Mike Kremer.