Patent ID: 7853415

Claim:
A computer program product tangibly embodied in a non-transitory machine-readable storage medium, wherein the computer program product comprises instructions that, when read by a machine, operate to cause data processing apparatus to: determine a standard density value for each of a plurality of input pairs, each input pair including a temperature value and a pressure value; determine a density approximation for each input pair using a virial equation expressed by: B ⁡ ( T ) = a + b T + c T 3 + d T 8 + e T 9 , wherein B(T) represents molar density expressed in units of m 3 /kg·mol, T represents temperature in degrees Kelvin, and a to e are coefficients tailored to the standard density value of the each input pair; determine a density error ratio for each input pair based on the standard density value and the density approximation of the each input pair; scale the density error ratios; and store the scaled density error ratios in a table for later retrieval.