Maybe consider trying a DS1603L. If the "depth" of liquid is known, then you could also use that sensor to "measure" the depth, and the difference between the known and measured depths would vary depending on the fluid type.
Maybe consider trying a DS1603L. If the "depth" of liquid is known, then you could also use that sensor to "measure" the depth, and the difference between the known and measured depths would vary depending on the fluid type.