Upstream density is calculated as follows:

Symbol | Description | Units |
---|---|---|

ρ | Density at the upstream conditions | kg/m^{3} |

ρ_{std} |
Standard density | kg/m^{3} |

P | Pressure at the upstream conditions | bar a |

P_{std} |
Standard pressure | bar a |

T | Temperature at the upstream conditions | K |

T_{std} |
Standard temperature | K |

Z | Compression factor at the upstream conditions | - |

Z_{std} |
Compression factor at standard conditions | - |