UN-401: Liquid Turbine(density based water cut, prover)


Calculates the uncertainty in observed volume, mass and standard volume flowrate for a liquid flow through a turbine with an online prover and/or master meter. Meter observed volume flowrate uncertainties are determined from proving statistics as per API MPMS 4.2. Line and standard densities and their uncertainties are performed by user-selected density referral calculations. Pressure, temperature and measured density uncertainties are determined using the technical specification for the transmitters selected from the integrated transmitter selection tool. The module replicates the “Net Oil” calculations to determine the “Net Oil” and “Water” mass flowrates and determines the associated uncertainties in these outputs. The “Net Oil” calculation require standard density inputs for both the oil and water phases, and uses the relevant standards for Ctl and Cpl to convert these densities to line conditions.


The General tab is used to enter information, which is saved along with the uncertainty calculation and included in reports which are generated.

The tabs used for inputting data and calculating the uncertainty in the individual components of the uncertainty can be seen along the top of the module window.

The report tab is only visible once the calculation has been run and will not be visible if any parameters are changed until the calculation has been run once more.



Pressure units

This section gives the option of entering the pressure as either an absolute value or as a gauge value with reference to atmospheric (barometric) pressure. If Absolute is selected inputs are required for Absolute pressure and Atmospheric pressure and if Gauge is selected inputs are required for Gauge pressure and Atmospheric pressure. This ensures that whichever is chosen both the gauge and Absolute pressure value is available to other sections of the module.

For example: the Density calculation tab may require an absolute pressure to perform an AGA 8 calculation and the Gauge pressure may be used for the pressure transmitter calculation.

Absolute pressure – the Atmospheric pressure = Gauge pressure


Volume flow rate

The volume flow rate of the liquid passing through the turbine meter.


This is the measured temperature of the stream.


This is the line pressure of the stream measured.

Inputs are required for both Absolute and Atmospheric pressure.

Densitometer pressure

The pressure reading on the densitometer.

Densitometer temperature

The temperature reading on the densitometer.


The density of the liquid flowing through the turbine meter.


The outputs section shows the calculated flow rate and uncertainty taken from the Flow Rate tab.

Calculation Blocks

The following blocks are used within this uncertainty module:



Measured Density


Turbine Meter with Oil Prover

Net Oil Flow Rates