Upstream density is calculated as follows:

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

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

ρ_{i} |
Observed density | kg/m^{3} |

P | Pressure at the upstream conditions | bar a |

P_{D} |
Pressure at the flow meter | bar a |

T | Temperature at the upstream conditions | K |

T_{D} |
Temperature at the flow meter | K |

Z | Compression factor at the upstream conditions | - |

Z_{D} |
Compression factor corresponding with observed density | - |