A method and apparatus for performing a fiscal measurement of at least one characteristic of an aerated fluid flowing within a pipe is provided, wherein the apparatus includes at least one metering device for determining the mixture density of the fluid, the speed of sound of the fluid and the speed of sound of the liquid portion of the fluid, wherein the at least one metering device generates meter data responsive to the mixture density of the fluid, the speed of sound of the fluid and the speed of sound of the liquid portion of the fluid. The apparatus further includes a processing device communicated with the at least one metering device, wherein the processing device receives the meter data and processes the meter data to generate the at least one fiscal measurement.