VortexMaster FSV430, FSV450 SwirlMaster FSS430, FSS450 | CI/FSV/FSS/430/450-EN Rev. G 55
Calculation of the density
The density calculation method is selected using the "Density Selection" parameter.
Media type Calculation method Description
Saturated Steam Calc. From T The steam density is calculated in accordance with the saturated steam curve using the measured
temperature value from the internal temperature sensor.
If using an FSS430 / FSV430 without optional internal temperature sensor, a constant (parameter
"Preset Int.Temp") must be entered for the temperature. Alternatively, an external temperature
transmitter can also be connected with HART-communication.
Calc. From P
The steam density is calculated according to IAPWS-IF97 with a measured pressure value.
The measured pressure value can either be supplied via the analog input, the HART input, or as a
constant (parameter "Preset Pressure(abs)").
Calc. From P&T The steam density is calculated in accordance with IAPWS-IF97 using the measured temperature
value from the internal temperature sensor and a measured pressure value.
The measured pressure value can either be supplied via the analog input, the HART input, or as a
constant (parameter "Preset Pressure(abs)").
If using an FSS430 / FSV430 without optional internal temperature sensor, a constant (parameter
"Preset Int.Temp") must be entered for the temperature. Alternatively, an external temperature
transmitter can also be connected with HART-communication.
If the steam is not saturated steam, a warning is generated by the device, the density and the energy
content of the steam are calculated with the current values as overheated steam.
If the steam temperature is too low (wet steam), the density (and the energy if applicable) will be
calculated in accordance with the saturated steam curve based on the measured value from the
internal or external temperature sensor.
Ext. Density
The steam mass is calculated using the density value that is supplied either via the analog input, the
HART input, or as a constant (parameter "Preset Density ").
Detection of wet steam / overheated steam is not possible with this calculation method.
Overheated Steam Calc. From P&T The steam density is calculated in accordance with IAPWS-IF97 using the measured temperature
value from the internal temperature sensor and a measured pressure value.
The measured pressure value can either be supplied via the analog input, the HART input, or as a
constant (parameter "Preset Pressure(abs)").
If using an FSS430 / FSV430 without optional internal temperature sensor, a constant (parameter
"Preset Int.Temp") must be entered for the temperature. Alternatively, an external temperature
transmitter can also be connected with HART-communication.
If the steam temperature is too low relative to the pressure measured value, the density and energy
calculation is automatically converted to condensate density and condensate energy.
Upon reaching the steam state, it is again automatically converted to steam density and steam energy.
NOTICE
If the automatic switching between steam and condensate density is undesirable, the parameter
Water/Steam Type „Saturated Steam" must be selected! This means that the correct steam density
and enthalpy are always calculated even in the case of overheated steam.
Ext. Density
The steam mass is calculated using the density value that is supplied either via the analog input, the
HART input, or as a constant (parameter "Preset Density ").
Detection of wet steam / overheated steam is not possible with this calculation method.