A meter controller comprises a first input, a second input, and a processor. The processor is configured to receive first and second volumetric flow measurements and to calculate a quasi fluid density value required to cause the first volumetric flow measurement to equal the second volumetric flow measurement. The processor is further configured to subtract a first fluid density value from the quasi fluid density value for calculating a density correction factor. The density correction factor is subtracted from the first fluid density value to calculate a corrected second density value. The corrected second density value is applied to at least one of the first volumetric flow measurement and the second volumetric flow measurement for calculating a mass flow rate measurement.