Fitting
Mass density
| Symbol | Definition | Unit |
| P ref | Reference pressure | Pa |
| T refD | Mass density reference temperature T refD | °C |
| r ref | Mass density at T refD and P ref | kg/m3 |
| a | Mass density first order temperature coefficient at T refD and P ref | K-1 |
| b | Mass density second order temperature coefficient at T refD and P ref | K-2 |
Note: The reference pressure mentioned in the previous table is
the one considered for defining the gas specific heat.
Note: For a given temperature, the gas density (kg/m3)
changes with the pressure following the perfect gas law.
The mass density ρ computed at a pressure P is computed as below:
